31923391 has 2 divisors, whose sum is σ = 31923392. Its totient is φ = 31923390.

The previous prime is 31923389. The next prime is 31923407. The reversal of 31923391 is 19332913.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31923391 - 2¹ = 31923389 is a prime.

Together with 31923389, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31923301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15961695 + 15961696.

It is an arithmetic number, because the mean of its divisors is an integer number (15961696).

Almost surely, 2^31923391 is an apocalyptic number.

31923391 is a deficient number, since it is larger than the sum of its proper divisors (1).

31923391 is an equidigital number, since it uses as much as digits as its factorization.

31923391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4374, while the sum is 31.

The square root of 31923391 is about 5650.0788490073. The cubic root of 31923391 is about 317.2266554314.

The spelling of 31923391 in words is "thirty-one million, nine hundred twenty-three thousand, three hundred ninety-one".