21621761267117 has 48 divisors (see below), whose sum is σ = 24577186529280. Its totient is φ = 18987634116000.

The previous prime is 21621761267089. The next prime is 21621761267123. The reversal of 21621761267117 is 71176216712612.

It is not a de Polignac number, because 21621761267117 - 2³⁴ = 21604581397933 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21621761266117) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7277602442 + ... + 7277605412.

It is an arithmetic number, because the mean of its divisors is an integer number (512024719360).

Almost surely, 2^{21621761267117} is an apocalyptic number.

It is an amenable number.

21621761267117 is a deficient number, since it is larger than the sum of its proper divisors (2955425262163).

21621761267117 is a wasteful number, since it uses less digits than its factorization.

21621761267117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5886 (or 5875 counting only the distinct ones).

The product of its digits is 592704, while the sum is 50.

Adding to 21621761267117 its reverse (71176216712612), we get a palindrome (92797977979729).

The spelling of 21621761267117 in words is "twenty-one trillion, six hundred twenty-one billion, seven hundred sixty-one million, two hundred sixty-seven thousand, one hundred seventeen".