21623522055631 has 4 divisors (see below), whose sum is σ = 21656334684600. Its totient is φ = 21590709426664.

The previous prime is 21623522055607. The next prime is 21623522055643. The reversal of 21623522055631 is 13655022532612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21623522055631 is a prime.

It is a super-2 number, since 2×21623522055631² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21623522055601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16406313496 + ... + 16406314813.

It is an arithmetic number, because the mean of its divisors is an integer number (5414083671150).

Almost surely, 2^{21623522055631} is an apocalyptic number.

21623522055631 is a deficient number, since it is larger than the sum of its proper divisors (32812628969).

21623522055631 is an equidigital number, since it uses as much as digits as its factorization.

21623522055631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32812628968.

The product of its (nonzero) digits is 648000, while the sum is 43.

The spelling of 21623522055631 in words is "twenty-one trillion, six hundred twenty-three billion, five hundred twenty-two million, fifty-five thousand, six hundred thirty-one".