31291943 has 2 divisors, whose sum is σ = 31291944. Its totient is φ = 31291942.

The previous prime is 31291903. The next prime is 31291969. The reversal of 31291943 is 34919213.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31291943 - 2²² = 27097639 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31291903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15645971 + 15645972.

It is an arithmetic number, because the mean of its divisors is an integer number (15645972).

Almost surely, 2^31291943 is an apocalyptic number.

31291943 is a deficient number, since it is larger than the sum of its proper divisors (1).

31291943 is an equidigital number, since it uses as much as digits as its factorization.

31291943 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 32.

The square root of 31291943 is about 5593.9201817688. The cubic root of 31291943 is about 315.1211191240.

The spelling of 31291943 in words is "thirty-one million, two hundred ninety-one thousand, nine hundred forty-three".