31312961 has 2 divisors, whose sum is σ = 31312962. Its totient is φ = 31312960.

The previous prime is 31312949. The next prime is 31312973. The reversal of 31312961 is 16921313.

It is a balanced prime because it is at equal distance from previous prime (31312949) and next prime (31312973).

It can be written as a sum of positive squares in only one way, i.e., 30250000 + 1062961 = 5500^2 + 1031^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31312961 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31312961.

It is not a weakly prime, because it can be changed into another prime (31312921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15656480 + 15656481.

It is an arithmetic number, because the mean of its divisors is an integer number (15656481).

Almost surely, 2^31312961 is an apocalyptic number.

It is an amenable number.

31312961 is a deficient number, since it is larger than the sum of its proper divisors (1).

31312961 is an equidigital number, since it uses as much as digits as its factorization.

31312961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 972, while the sum is 26.

The square root of 31312961 is about 5595.7985131704. The cubic root of 31312961 is about 315.1916562731.

The spelling of 31312961 in words is "thirty-one million, three hundred twelve thousand, nine hundred sixty-one".