31971761 has 2 divisors, whose sum is σ = 31971762. Its totient is φ = 31971760.

The previous prime is 31971743. The next prime is 31971763. The reversal of 31971761 is 16717913.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31080625 + 891136 = 5575^2 + 944^2 .

It is a cyclic number.

It is not a de Polignac number, because 31971761 - 2⁶ = 31971697 is a prime.

It is a super-2 number, since 2×31971761² = 2044387002882242, which contains 22 as substring.

Together with 31971763, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31971763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15985880 + 15985881.

It is an arithmetic number, because the mean of its divisors is an integer number (15985881).

Almost surely, 2^31971761 is an apocalyptic number.

It is an amenable number.

31971761 is a deficient number, since it is larger than the sum of its proper divisors (1).

31971761 is an equidigital number, since it uses as much as digits as its factorization.

31971761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7938, while the sum is 35.

The square root of 31971761 is about 5654.3577000399. The cubic root of 31971761 is about 317.3867941211.

The spelling of 31971761 in words is "thirty-one million, nine hundred seventy-one thousand, seven hundred sixty-one".