31680002891 has 2 divisors, whose sum is σ = 31680002892. Its totient is φ = 31680002890.

The previous prime is 31680002819. The next prime is 31680002899. The reversal of 31680002891 is 19820008613.

Together with previous prime (31680002819) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31680002891 - 2¹⁰ = 31680001867 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (31680002899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15840001445 + 15840001446.

It is an arithmetic number, because the mean of its divisors is an integer number (15840001446).

Almost surely, 2^31680002891 is an apocalyptic number.

31680002891 is a deficient number, since it is larger than the sum of its proper divisors (1).

31680002891 is an equidigital number, since it uses as much as digits as its factorization.

31680002891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 38.

The spelling of 31680002891 in words is "thirty-one billion, six hundred eighty million, two thousand, eight hundred ninety-one".