21521044155123 has 64 divisors (see below), whose sum is σ = 32657804826240. Its totient is φ = 14002796851200.

The previous prime is 21521044155049. The next prime is 21521044155181. The reversal of 21521044155123 is 32155144012512.

21521044155123 is a `hidden beast` number, since 2 + 1 + 5 + 210 + 4 + 415 + 5 + 1 + 23 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-21521044155123 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21521044155623) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 109850911 + ... + 110046647.

It is an arithmetic number, because the mean of its divisors is an integer number (510278200410).

Almost surely, 2^{21521044155123} is an apocalyptic number.

21521044155123 is a deficient number, since it is larger than the sum of its proper divisors (11136760671117).

21521044155123 is a wasteful number, since it uses less digits than its factorization.

21521044155123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196325 (or 196319 counting only the distinct ones).

The product of its (nonzero) digits is 48000, while the sum is 36.

Adding to 21521044155123 its reverse (32155144012512), we get a palindrome (53676188167635).

The spelling of 21521044155123 in words is "twenty-one trillion, five hundred twenty-one billion, forty-four million, one hundred fifty-five thousand, one hundred twenty-three".