31906243 has 2 divisors, whose sum is σ = 31906244. Its totient is φ = 31906242.

The previous prime is 31906219. The next prime is 31906249. The reversal of 31906243 is 34260913.

It is a strong prime.

It is an emirp because it is prime and its reverse (34260913) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31906243 - 2⁵ = 31906211 is a prime.

It is not a weakly prime, because it can be changed into another prime (31906249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15953121 + 15953122.

It is an arithmetic number, because the mean of its divisors is an integer number (15953122).

Almost surely, 2^31906243 is an apocalyptic number.

31906243 is a deficient number, since it is larger than the sum of its proper divisors (1).

31906243 is an equidigital number, since it uses as much as digits as its factorization.

31906243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 31906243 is about 5648.5611442207. The cubic root of 31906243 is about 317.1698446643.

The spelling of 31906243 in words is "thirty-one million, nine hundred six thousand, two hundred forty-three".