31660577213 has 4 divisors (see below), whose sum is σ = 31705233180. Its totient is φ = 31615921248.

The previous prime is 31660577183. The next prime is 31660577237. The reversal of 31660577213 is 31277506613.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16892980729 + 14767596484 = 129973^2 + 121522^2 .

It is a cyclic number.

It is not a de Polignac number, because 31660577213 - 2⁶ = 31660577149 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31660577293) 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, 22326920 + ... + 22328337.

It is an arithmetic number, because the mean of its divisors is an integer number (7926308295).

Almost surely, 2^31660577213 is an apocalyptic number.

It is an amenable number.

31660577213 is a deficient number, since it is larger than the sum of its proper divisors (44655967).

31660577213 is an equidigital number, since it uses as much as digits as its factorization.

31660577213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44655966.

The product of its (nonzero) digits is 158760, while the sum is 41.

The spelling of 31660577213 in words is "thirty-one billion, six hundred sixty million, five hundred seventy-seven thousand, two hundred thirteen".