15985556356 has 81 divisors (see below), whose sum is σ = 35812954821. Its totient is φ = 6220552800.

The previous prime is 15985556309. The next prime is 15985556369. The reversal of 15985556356 is 65365558951.

The square root of 15985556356 is 126434.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 4364716356 + 11620840000 = 66066^2 + 107800^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 15985556356.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 19470426 + ... + 19471246.

Almost surely, 2^15985556356 is an apocalyptic number.

15985556356 is the 126434-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15985556356

15985556356 is an abundant number, since it is smaller than the sum of its proper divisors (19827398465).

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

15985556356 is an equidigital number, since it uses as much as digits as its factorization.

15985556356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1682 (or 841 counting only the distinct ones).

The product of its digits is 24300000, while the sum is 58.

The spelling of 15985556356 in words is "fifteen billion, nine hundred eighty-five million, five hundred fifty-six thousand, three hundred fifty-six".