31690978811 has 2 divisors, whose sum is σ = 31690978812. Its totient is φ = 31690978810.

The previous prime is 31690978799. The next prime is 31690978819. The reversal of 31690978811 is 11887909613.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31690978811 - 2³⁰ = 30617236987 is a prime.

It is not a weakly prime, because it can be changed into another prime (31690978819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15845489405 + 15845489406.

It is an arithmetic number, because the mean of its divisors is an integer number (15845489406).

Almost surely, 2^31690978811 is an apocalyptic number.

31690978811 is a deficient number, since it is larger than the sum of its proper divisors (1).

31690978811 is an equidigital number, since it uses as much as digits as its factorization.

31690978811 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 653184, while the sum is 53.

The spelling of 31690978811 in words is "thirty-one billion, six hundred ninety million, nine hundred seventy-eight thousand, eight hundred eleven".