31312221313 has 4 divisors (see below), whose sum is σ = 31314364228. Its totient is φ = 31310078400.

The previous prime is 31312221173. The next prime is 31312221319.

31312221313 is nontrivially palindromic in base 10.

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 17186423409 + 14125797904 = 131097^2 + 118852^2 .

It is a cyclic number.

It is not a de Polignac number, because 31312221313 - 2²¹ = 31310124161 is a prime.

It is a super-3 number, since 3×31312221313³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31312221319) 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, 1049388 + ... + 1078813.

It is an arithmetic number, because the mean of its divisors is an integer number (7828591057).

Almost surely, 2^31312221313 is an apocalyptic number.

It is an amenable number.

31312221313 is a deficient number, since it is larger than the sum of its proper divisors (2142915).

31312221313 is a wasteful number, since it uses less digits than its factorization.

31312221313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2142914.

The product of its digits is 648, while the sum is 22.

Multiplying 31312221313 by its sum of digits (22), we get a palindrome (688868868886).

The spelling of 31312221313 in words is "thirty-one billion, three hundred twelve million, two hundred twenty-one thousand, three hundred thirteen".