15972854921856 has 640 divisors, whose sum is σ = 56132600832000. Its totient is φ = 4412167096320.

The previous prime is 15972854921839. The next prime is 15972854921893. The reversal of 15972854921856 is 65812945827951.

15972854921856 is a `hidden beast` number, since 1 + 5 + 9 + 7 + 2 + 8 + 549 + 21 + 8 + 56 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 2832565885 + ... + 2832571523.

It is an arithmetic number, because the mean of its divisors is an integer number (87707188800).

Almost surely, 2^{15972854921856} is an apocalyptic number.

15972854921856 is a gapful number since it is divisible by the number (16) 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 15972854921856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28066300416000).

15972854921856 is an abundant number, since it is smaller than the sum of its proper divisors (40159745910144).

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

15972854921856 is a wasteful number, since it uses less digits than its factorization.

15972854921856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6962 (or 6941 counting only the distinct ones).

The product of its digits is 435456000, while the sum is 72.

The spelling of 15972854921856 in words is "fifteen trillion, nine hundred seventy-two billion, eight hundred fifty-four million, nine hundred twenty-one thousand, eight hundred fifty-six".