21536891895563 has 16 divisors (see below), whose sum is σ = 23723642342400. Its totient is φ = 19388295276480.

The previous prime is 21536891895551. The next prime is 21536891895581. The reversal of 21536891895563 is 36559819863512.

It is a cyclic number.

It is not a de Polignac number, because 21536891895563 - 2²⁴ = 21536875118347 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21536891895503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37876103 + ... + 38440511.

It is an arithmetic number, because the mean of its divisors is an integer number (1482727646400).

Almost surely, 2^{21536891895563} is an apocalyptic number.

21536891895563 is a deficient number, since it is larger than the sum of its proper divisors (2186750446837).

21536891895563 is a wasteful number, since it uses less digits than its factorization.

21536891895563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 598202.

The product of its digits is 419904000, while the sum is 71.

The spelling of 21536891895563 in words is "twenty-one trillion, five hundred thirty-six billion, eight hundred ninety-one million, eight hundred ninety-five thousand, five hundred sixty-three".