21945196900 has 36 divisors (see below), whose sum is σ = 51950268720. Its totient is φ = 7980071200.

The previous prime is 21945196891. The next prime is 21945196943. The reversal of 21945196900 is 969154912.

It is a happy number.

It is a super-2 number, since 2×21945196900² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9973990 + ... + 9976189.

It is an arithmetic number, because the mean of its divisors is an integer number (1443063020).

Almost surely, 2^21945196900 is an apocalyptic number.

21945196900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21945196900 is an abundant number, since it is smaller than the sum of its proper divisors (30005071820).

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

21945196900 is a wasteful number, since it uses less digits than its factorization.

21945196900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19950204 (or 19950197 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 46.

The spelling of 21945196900 in words is "twenty-one billion, nine hundred forty-five million, one hundred ninety-six thousand, nine hundred".