21911626881 has 6 divisors (see below), whose sum is σ = 31650127730. Its totient is φ = 14607751248.

The previous prime is 21911626771. The next prime is 21911626897. The reversal of 21911626881 is 18862611912.

It is a happy number.

21911626881 is a `hidden beast` number, since 2 + 1 + 9 + 11 + 626 + 8 + 8 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21788416881 + 123210000 = 147609^2 + 11100^2 .

It is not a de Polignac number, because 21911626881 - 2¹³ = 21911618689 is a prime.

It is a super-2 number, since 2×21911626881² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21911626081) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1217312596 + ... + 1217312613.

Almost surely, 2^21911626881 is an apocalyptic number.

It is an amenable number.

21911626881 is a deficient number, since it is larger than the sum of its proper divisors (9738500849).

21911626881 is a wasteful number, since it uses less digits than its factorization.

21911626881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2434625215 (or 2434625212 counting only the distinct ones).

The product of its digits is 82944, while the sum is 45.

The spelling of 21911626881 in words is "twenty-one billion, nine hundred eleven million, six hundred twenty-six thousand, eight hundred eighty-one".