15815326081 has 9 divisors (see below), whose sum is σ = 16063456899. Its totient is φ = 15570976344.

The previous prime is 15815326073. The next prime is 15815326091. The reversal of 15815326081 is 18062351851.

It is a happy number.

The square root of 15815326081 is 125759.

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., 9899255025 + 5916071056 = 99495^2 + 76916^2 .

It is not a de Polignac number, because 15815326081 - 2³ = 15815326073 is a prime.

It is a super-2 number, since 2×15815326081² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15815326031) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 8424915 + ... + 8426791.

Almost surely, 2^15815326081 is an apocalyptic number.

15815326081 is the 125759-th square number.

15815326081 is the 62880-th centered octagonal number.

It is an amenable number.

15815326081 is a deficient number, since it is larger than the sum of its proper divisors (248130818).

15815326081 is an frugal number, since it uses more digits than its factorization.

15815326081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3888 (or 1944 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 40.

Multiplying 15815326081 by its product of nonzero digits (57600), we get a square (910962782265600 = 30182160²).

The spelling of 15815326081 in words is "fifteen billion, eight hundred fifteen million, three hundred twenty-six thousand, eighty-one".