31822421 has 2 divisors, whose sum is σ = 31822422. Its totient is φ = 31822420.

The previous prime is 31822411. The next prime is 31822423. The reversal of 31822421 is 12422813.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25140196 + 6682225 = 5014^2 + 2585^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31822421 is a prime.

Together with 31822423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31822423) 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, 15911210 + 15911211.

It is an arithmetic number, because the mean of its divisors is an integer number (15911211).

Almost surely, 2^31822421 is an apocalyptic number.

It is an amenable number.

31822421 is a deficient number, since it is larger than the sum of its proper divisors (1).

31822421 is an equidigital number, since it uses as much as digits as its factorization.

31822421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 768, while the sum is 23.

The square root of 31822421 is about 5641.1364989690. The cubic root of 31822421 is about 316.8918517726.

The spelling of 31822421 in words is "thirty-one million, eight hundred twenty-two thousand, four hundred twenty-one".