21635370023 has 2 divisors, whose sum is σ = 21635370024. Its totient is φ = 21635370022.

The previous prime is 21635369999. The next prime is 21635370041. The reversal of 21635370023 is 32007353612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21635370023 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21635370083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10817685011 + 10817685012.

It is an arithmetic number, because the mean of its divisors is an integer number (10817685012).

Almost surely, 2^21635370023 is an apocalyptic number.

21635370023 is a deficient number, since it is larger than the sum of its proper divisors (1).

21635370023 is an equidigital number, since it uses as much as digits as its factorization.

21635370023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 32.

The spelling of 21635370023 in words is "twenty-one billion, six hundred thirty-five million, three hundred seventy thousand, twenty-three".