31811964641 has 2 divisors, whose sum is σ = 31811964642. Its totient is φ = 31811964640.

The previous prime is 31811964607. The next prime is 31811964763. The reversal of 31811964641 is 14646911813.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27333678241 + 4478286400 = 165329^2 + 66920^2 .

It is a cyclic number.

It is not a de Polignac number, because 31811964641 - 2³⁰ = 30738222817 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31811964592 and 31811964601.

It is not a weakly prime, because it can be changed into another prime (31811964341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15905982320 + 15905982321.

It is an arithmetic number, because the mean of its divisors is an integer number (15905982321).

Almost surely, 2^31811964641 is an apocalyptic number.

It is an amenable number.

31811964641 is a deficient number, since it is larger than the sum of its proper divisors (1).

31811964641 is an equidigital number, since it uses as much as digits as its factorization.

31811964641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 44.

The spelling of 31811964641 in words is "thirty-one billion, eight hundred eleven million, nine hundred sixty-four thousand, six hundred forty-one".