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30857940 = 22325251683
BaseRepresentation
bin111010110110…
…1101011010100
32011001202010200
41311231223110
530344423230
63021220500
7523200561
oct165555324
964052120
1030857940
1116467033
12a401730
136515649
144153868
152a98160
hex1d6dad4

30857940 has 72 divisors (see below), whose sum is σ = 94112928. Its totient is φ = 8184000.

The previous prime is 30857933. The next prime is 30857947. The reversal of 30857940 is 4975803.

It is an interprime number because it is at equal distance from previous prime (30857933) and next prime (30857947).

It is a super-2 number, since 2×308579402 = 1904424922087200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 30857895 and 30857904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30857947) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 44839 + ... + 45521.

It is an arithmetic number, because the mean of its divisors is an integer number (1307124).

It is a vampire number, since it can be written as 40987530 (with its own digits).

Almost surely, 230857940 is an apocalyptic number.

30857940 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 30857940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47056464).

30857940 is an abundant number, since it is smaller than the sum of its proper divisors (63254988).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

30857940 is a wasteful number, since it uses less digits than its factorization.

30857940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 949 (or 944 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 30857940 is about 5554.9923492297. The cubic root of 30857940 is about 313.6574760377.

It can be divided in two parts, 3085 and 7940, that added together give a square (11025 = 1052).

The spelling of 30857940 in words is "thirty million, eight hundred fifty-seven thousand, nine hundred forty".

Divisors: 1 2 3 4 5 6 9 10 12 15 18 20 30 36 45 60 90 180 251 502 683 753 1004 1255 1366 1506 2049 2259 2510 2732 3012 3415 3765 4098 4518 5020 6147 6830 7530 8196 9036 10245 11295 12294 13660 15060 20490 22590 24588 30735 40980 45180 61470 122940 171433 342866 514299 685732 857165 1028598 1542897 1714330 2057196 2571495 3085794 3428660 5142990 6171588 7714485 10285980 15428970 30857940