16315516581 has 32 divisors (see below), whose sum is σ = 28183357440. Its totient is φ = 8153037504.

The previous prime is 16315516577. The next prime is 16315516583. The reversal of 16315516581 is 18561551361.

It is not a de Polignac number, because 16315516581 - 2² = 16315516577 is a prime.

It is a super-2 number, since 2×16315516581² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16315516583) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1567545 + ... + 1577918.

It is an arithmetic number, because the mean of its divisors is an integer number (880729920).

Almost surely, 2^16315516581 is an apocalyptic number.

It is an amenable number.

16315516581 is a deficient number, since it is larger than the sum of its proper divisors (11867840859).

16315516581 is a wasteful number, since it uses less digits than its factorization.

16315516581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3145505.

The product of its digits is 108000, while the sum is 42.

The spelling of 16315516581 in words is "sixteen billion, three hundred fifteen million, five hundred sixteen thousand, five hundred eighty-one".