21889920756 has 72 divisors (see below), whose sum is σ = 57953066752. Its totient is φ = 6419318400.

The previous prime is 21889920743. The next prime is 21889920791. The reversal of 21889920756 is 65702998812.

It is a happy number.

It is a super-2 number, since 2×21889920756² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21889920696 and 21889920705.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 198145 + ... + 288168.

Almost surely, 2^21889920756 is an apocalyptic number.

It is an amenable number.

21889920756 is an abundant number, since it is smaller than the sum of its proper divisors (36063145996).

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

21889920756 is a wasteful number, since it uses less digits than its factorization.

21889920756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 486373 (or 486360 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 57.

The spelling of 21889920756 in words is "twenty-one billion, eight hundred eighty-nine million, nine hundred twenty thousand, seven hundred fifty-six".