21563231634444 has 12 divisors (see below), whose sum is σ = 50314207147064. Its totient is φ = 7187743878144.

The previous prime is 21563231634443. The next prime is 21563231634521. The reversal of 21563231634444 is 44443613236512.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 21563231634393 and 21563231634402.

It is not an unprimeable number, because it can be changed into a prime (21563231634443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 898467984757 + ... + 898467984780.

Almost surely, 2^{21563231634444} is an apocalyptic number.

It is an amenable number.

21563231634444 is an abundant number, since it is smaller than the sum of its proper divisors (28750975512620).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21563231634444 is a wasteful number, since it uses less digits than its factorization.

21563231634444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1796935969544 (or 1796935969542 counting only the distinct ones).

The product of its digits is 4976640, while the sum is 48.

The spelling of 21563231634444 in words is "twenty-one trillion, five hundred sixty-three billion, two hundred thirty-one million, six hundred thirty-four thousand, four hundred forty-four".