21926897538 has 32 divisors (see below), whose sum is σ = 53973902976. Its totient is φ = 5782917888.

The previous prime is 21926897537. The next prime is 21926897549. The reversal of 21926897538 is 83579862912.

It is a super-2 number, since 2×21926897538² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21926897537) 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, 20079031 + ... + 20080122.

It is an arithmetic number, because the mean of its divisors is an integer number (1686684468).

Almost surely, 2^21926897538 is an apocalyptic number.

21926897538 is an abundant number, since it is smaller than the sum of its proper divisors (32047005438).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21926897538 is a wasteful number, since it uses less digits than its factorization.

21926897538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40159178.

The product of its digits is 13063680, while the sum is 60.

The spelling of 21926897538 in words is "twenty-one billion, nine hundred twenty-six million, eight hundred ninety-seven thousand, five hundred thirty-eight".