Base | Representation |
---|---|
bin | 100100001011… |
… | …1010001111000 |
3 | 1022200202120020 |
4 | 1020113101320 |
5 | 14324012340 |
6 | 1514330440 |
7 | 320145210 |
oct | 110272170 |
9 | 38622506 |
10 | 18969720 |
11 | a787260 |
12 | 6429a20 |
13 | 3c124b3 |
14 | 273b240 |
15 | 19ea9d0 |
hex | 1217478 |
18969720 has 128 divisors (see below), whose sum is σ = 70986240. Its totient is φ = 3939840.
The previous prime is 18969701. The next prime is 18969767. The reversal of 18969720 is 2796981.
18969720 is a nontrivial binomial coefficient, being equal to C(6160, 2).
It is a Harshad number since it is a multiple of its sum of digits (42).
It is a congruent number.
It is an unprimeable number.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8214 + ... + 10266.
It is an arithmetic number, because the mean of its divisors is an integer number (554580).
Almost surely, 218969720 is an apocalyptic number.
18969720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.
18969720 is the 6159-th triangular number and also the 3080-th hexagonal number.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 18969720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35493120).
18969720 is an abundant number, since it is smaller than the sum of its proper divisors (52016520).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
18969720 is a wasteful number, since it uses less digits than its factorization.
18969720 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 2085 (or 2081 counting only the distinct ones).
The product of its (nonzero) digits is 54432, while the sum is 42.
The square root of 18969720 is about 4355.4242043686. The cubic root of 18969720 is about 266.6983365165.
The spelling of 18969720 in words is "eighteen million, nine hundred sixty-nine thousand, seven hundred twenty".
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