31956210161 has 2 divisors, whose sum is σ = 31956210162. Its totient is φ = 31956210160.

The previous prime is 31956210079. The next prime is 31956210203. The reversal of 31956210161 is 16101265913.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21048496561 + 10907713600 = 145081^2 + 104440^2 .

It is a cyclic number.

It is not a de Polignac number, because 31956210161 - 2²² = 31952015857 is a prime.

It is not a weakly prime, because it can be changed into another prime (31956270161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15978105080 + 15978105081.

It is an arithmetic number, because the mean of its divisors is an integer number (15978105081).

Almost surely, 2^31956210161 is an apocalyptic number.

It is an amenable number.

31956210161 is a deficient number, since it is larger than the sum of its proper divisors (1).

31956210161 is an equidigital number, since it uses as much as digits as its factorization.

31956210161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9720, while the sum is 35.

The spelling of 31956210161 in words is "thirty-one billion, nine hundred fifty-six million, two hundred ten thousand, one hundred sixty-one".