21163525761 has 24 divisors (see below), whose sum is σ = 32946248064. Its totient is φ = 12048795360.

The previous prime is 21163525751. The next prime is 21163525813. The reversal of 21163525761 is 16752536112.

It is not a de Polignac number, because 21163525761 - 2⁷ = 21163525633 is a prime.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21163525711) 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 23 ways as a sum of consecutive naturals, for example, 225790 + ... + 305463.

It is an arithmetic number, because the mean of its divisors is an integer number (1372760336).

Almost surely, 2^21163525761 is an apocalyptic number.

21163525761 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21163525761 is a deficient number, since it is larger than the sum of its proper divisors (11782722303).

21163525761 is a wasteful number, since it uses less digits than its factorization.

21163525761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 531541 (or 531534 counting only the distinct ones).

The product of its digits is 75600, while the sum is 39.

The spelling of 21163525761 in words is "twenty-one billion, one hundred sixty-three million, five hundred twenty-five thousand, seven hundred sixty-one".