16316331561 has 12 divisors (see below), whose sum is σ = 23577737092. Its totient is φ = 10873076256.

The previous prime is 16316331541. The next prime is 16316331571. The reversal of 16316331561 is 16513361361.

16316331561 is a `hidden beast` number, since 1 + 6 + 3 + 1 + 63 + 31 + 561 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 11711351961 + 4604979600 = 108219^2 + 67860^2 .

It is not a de Polignac number, because 16316331561 - 2⁷ = 16316331433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16316331511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 350026 + ... + 393891.

Almost surely, 2^16316331561 is an apocalyptic number.

It is an amenable number.

16316331561 is a deficient number, since it is larger than the sum of its proper divisors (7261405531).

16316331561 is a wasteful number, since it uses less digits than its factorization.

16316331561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 746360 (or 746357 counting only the distinct ones).

The product of its digits is 29160, while the sum is 36.

The spelling of 16316331561 in words is "sixteen billion, three hundred sixteen million, three hundred thirty-one thousand, five hundred sixty-one".