21933971 has 2 divisors, whose sum is σ = 21933972. Its totient is φ = 21933970.

The previous prime is 21933949. The next prime is 21934013. The reversal of 21933971 is 17933912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21933971 - 2⁶ = 21933907 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21933911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10966985 + 10966986.

It is an arithmetic number, because the mean of its divisors is an integer number (10966986).

Almost surely, 2^21933971 is an apocalyptic number.

21933971 is a deficient number, since it is larger than the sum of its proper divisors (1).

21933971 is an equidigital number, since it uses as much as digits as its factorization.

21933971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10206, while the sum is 35.

The square root of 21933971 is about 4683.3717554770. The cubic root of 21933971 is about 279.9233250938.

The spelling of 21933971 in words is "twenty-one million, nine hundred thirty-three thousand, nine hundred seventy-one".