21912735988 has 24 divisors (see below), whose sum is σ = 45051360480. Its totient is φ = 9194154720.

The previous prime is 21912735947. The next prime is 21912735991. The reversal of 21912735988 is 88953721912.

It is a happy number.

It is a super-2 number, since 2×21912735988² (a number of 21 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (55) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19153918 + ... + 19155061.

It is an arithmetic number, because the mean of its divisors is an integer number (1877140020).

Almost surely, 2^21912735988 is an apocalyptic number.

It is an amenable number.

21912735988 is an abundant number, since it is smaller than the sum of its proper divisors (23138624492).

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

21912735988 is a wasteful number, since it uses less digits than its factorization.

21912735988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38309007 (or 38309005 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 55.

The spelling of 21912735988 in words is "twenty-one billion, nine hundred twelve million, seven hundred thirty-five thousand, nine hundred eighty-eight".