31680696557 has 4 divisors (see below), whose sum is σ = 31683284316. Its totient is φ = 31678108800.

The previous prime is 31680696521. The next prime is 31680696569. The reversal of 31680696557 is 75569608613.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75569608613 = 1229 ⋅61488697.

It can be written as a sum of positive squares in 2 ways, for example, as 6369795721 + 25310900836 = 79811^2 + 159094^2 .

It is a cyclic number.

It is not a de Polignac number, because 31680696557 - 2⁶ = 31680696493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31680692557) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1275428 + ... + 1300029.

It is an arithmetic number, because the mean of its divisors is an integer number (7920821079).

Almost surely, 2^31680696557 is an apocalyptic number.

It is an amenable number.

31680696557 is a deficient number, since it is larger than the sum of its proper divisors (2587759).

31680696557 is a wasteful number, since it uses less digits than its factorization.

31680696557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2587758.

The product of its (nonzero) digits is 8164800, while the sum is 56.

The spelling of 31680696557 in words is "thirty-one billion, six hundred eighty million, six hundred ninety-six thousand, five hundred fifty-seven".