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28700784 = 243379491
BaseRepresentation
bin110110101111…
…1000001110000
32000000011002000
41231133001300
524321411114
62503054000
7465644520
oct155370160
960004060
1028700784
1115223362
129741300
135c3b818
143b51680
1527bde09
hex1b5f070

28700784 has 80 divisors (see below), whose sum is σ = 94160640. Its totient is φ = 8199360.

The previous prime is 28700783. The next prime is 28700813. The reversal of 28700784 is 48700782.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28700783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1722 + ... + 7769.

It is an arithmetic number, because the mean of its divisors is an integer number (1177008).

Almost surely, 228700784 is an apocalyptic number.

28700784 is a gapful number since it is divisible by the number (24) 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 28700784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47080320).

28700784 is an abundant number, since it is smaller than the sum of its proper divisors (65459856).

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

28700784 is a wasteful number, since it uses less digits than its factorization.

28700784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9515 (or 9503 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 36.

The square root of 28700784 is about 5357.3112659244. The cubic root of 28700784 is about 306.1713765126.

The spelling of 28700784 in words is "twenty-eight million, seven hundred thousand, seven hundred eighty-four".

Divisors: 1 2 3 4 6 7 8 9 12 14 16 18 21 24 27 28 36 42 48 54 56 63 72 84 108 112 126 144 168 189 216 252 336 378 432 504 756 1008 1512 3024 9491 18982 28473 37964 56946 66437 75928 85419 113892 132874 151856 170838 199311 227784 256257 265748 341676 398622 455568 512514 531496 597933 683352 797244 1025028 1062992 1195866 1366704 1594488 1793799 2050056 2391732 3188976 3587598 4100112 4783464 7175196 9566928 14350392 28700784