21621271264563 has 32 divisors (see below), whose sum is σ = 29868183642112. Its totient is φ = 13897711728000.

The previous prime is 21621271264511. The next prime is 21621271264591. The reversal of 21621271264563 is 36546217212612.

It is a happy number.

It is not a de Polignac number, because 21621271264563 - 2¹³ = 21621271256371 is a prime.

It is a super-3 number, since 3×21621271264563³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21621271268563) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 409599270 + ... + 409652052.

It is an arithmetic number, because the mean of its divisors is an integer number (933380738816).

Almost surely, 2^{21621271264563} is an apocalyptic number.

21621271264563 is a deficient number, since it is larger than the sum of its proper divisors (8246912377549).

21621271264563 is a wasteful number, since it uses less digits than its factorization.

21621271264563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68995.

The product of its digits is 1451520, while the sum is 48.

The spelling of 21621271264563 in words is "twenty-one trillion, six hundred twenty-one billion, two hundred seventy-one million, two hundred sixty-four thousand, five hundred sixty-three".