15816080644 has 81 divisors (see below), whose sum is σ = 34914757941. Its totient is φ = 6247856160.

The previous prime is 15816080627. The next prime is 15816080669. The reversal of 15816080644 is 44608061851.

The square root of 15816080644 is 125762.

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., 2339656900 + 13476423744 = 48370^2 + 116088^2 .

It is a super-2 number, since 2×15816080644² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 15816080644.

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, 22888339 + ... + 22889029.

Almost surely, 2^15816080644 is an apocalyptic number.

15816080644 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

15816080644 is the 125762-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15816080644

15816080644 is an abundant number, since it is smaller than the sum of its proper divisors (19098677297).

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

15816080644 is an equidigital number, since it uses as much as digits as its factorization.

15816080644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1426 (or 713 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 43.

The spelling of 15816080644 in words is "fifteen billion, eight hundred sixteen million, eighty thousand, six hundred forty-four".