21507535256023 has 2 divisors, whose sum is σ = 21507535256024. Its totient is φ = 21507535256022.

The previous prime is 21507535255993. The next prime is 21507535256047. The reversal of 21507535256023 is 32065253570512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21507535256023 - 2¹³ = 21507535247831 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21507535256083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10753767628011 + 10753767628012.

It is an arithmetic number, because the mean of its divisors is an integer number (10753767628012).

Almost surely, 2^{21507535256023} is an apocalyptic number.

21507535256023 is a deficient number, since it is larger than the sum of its proper divisors (1).

21507535256023 is an equidigital number, since it uses as much as digits as its factorization.

21507535256023 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1890000, while the sum is 46.

The spelling of 21507535256023 in words is "twenty-one trillion, five hundred seven billion, five hundred thirty-five million, two hundred fifty-six thousand, twenty-three".