31211313313 has 4 divisors (see below), whose sum is σ = 31242619540. Its totient is φ = 31180007088.

The previous prime is 31211313271. The next prime is 31211313347. The reversal of 31211313313 is 31331311213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31331311213 = 80407 ⋅389659.

It can be written as a sum of positive squares in 2 ways, for example, as 19557463104 + 11653850209 = 139848^2 + 107953^2 .

It is a cyclic number.

It is not a de Polignac number, because 31211313313 - 2⁹ = 31211312801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31211313383) 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, 15651618 + ... + 15653611.

It is an arithmetic number, because the mean of its divisors is an integer number (7810654885).

Almost surely, 2^31211313313 is an apocalyptic number.

It is an amenable number.

31211313313 is a deficient number, since it is larger than the sum of its proper divisors (31306227).

31211313313 is an equidigital number, since it uses as much as digits as its factorization.

31211313313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31306226.

The product of its digits is 486, while the sum is 22.

Adding to 31211313313 its reverse (31331311213), we get a palindrome (62542624526).

The spelling of 31211313313 in words is "thirty-one billion, two hundred eleven million, three hundred thirteen thousand, three hundred thirteen".