21163553553 has 16 divisors (see below), whose sum is σ = 28921842432. Its totient is φ = 13757520000.

The previous prime is 21163553533. The next prime is 21163553591. The reversal of 21163553553 is 35535536112.

It is a de Polignac number, because none of the positive numbers 2^k-21163553553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21163553533) 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 15 ways as a sum of consecutive naturals, for example, 188568 + ... + 279078.

It is an arithmetic number, because the mean of its divisors is an integer number (1807615152).

Almost surely, 2^21163553553 is an apocalyptic number.

It is an amenable number.

21163553553 is a deficient number, since it is larger than the sum of its proper divisors (7758288879).

21163553553 is a wasteful number, since it uses less digits than its factorization.

21163553553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92456.

The product of its digits is 202500, while the sum is 39.

The spelling of 21163553553 in words is "twenty-one billion, one hundred sixty-three million, five hundred fifty-three thousand, five hundred fifty-three".