31321313 has 2 divisors, whose sum is σ = 31321314. Its totient is φ = 31321312.

The previous prime is 31321309. The next prime is 31321319. The reversal of 31321313 is 31312313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28815424 + 2505889 = 5368^2 + 1583^2 .

It is a cyclic number.

It is not a de Polignac number, because 31321313 - 2² = 31321309 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31321291 and 31321300.

It is not a weakly prime, because it can be changed into another prime (31321319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15660656 + 15660657.

It is an arithmetic number, because the mean of its divisors is an integer number (15660657).

Almost surely, 2^31321313 is an apocalyptic number.

It is an amenable number.

31321313 is a deficient number, since it is larger than the sum of its proper divisors (1).

31321313 is an equidigital number, since it uses as much as digits as its factorization.

31321313 is an evil number, because the sum of its binary digits is even.

The product of its digits is 162, while the sum is 17.

The square root of 31321313 is about 5596.5447376037. The cubic root of 31321313 is about 315.2196771162.

Adding to 31321313 its reverse (31312313), we get a palindrome (62633626).

The spelling of 31321313 in words is "thirty-one million, three hundred twenty-one thousand, three hundred thirteen".