21371955023 has 2 divisors, whose sum is σ = 21371955024. Its totient is φ = 21371955022.

The previous prime is 21371955013. The next prime is 21371955049. The reversal of 21371955023 is 32055917312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21371955023 - 2²² = 21367760719 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21371955013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10685977511 + 10685977512.

It is an arithmetic number, because the mean of its divisors is an integer number (10685977512).

Almost surely, 2^21371955023 is an apocalyptic number.

21371955023 is a deficient number, since it is larger than the sum of its proper divisors (1).

21371955023 is an equidigital number, since it uses as much as digits as its factorization.

21371955023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56700, while the sum is 38.

The spelling of 21371955023 in words is "twenty-one billion, three hundred seventy-one million, nine hundred fifty-five thousand, twenty-three".