21407663872 has 36 divisors (see below), whose sum is σ = 48836237296. Its totient is φ = 9174712320.

The previous prime is 21407663741. The next prime is 21407663887. The reversal of 21407663872 is 27836670412.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5971329 + ... + 5974912.

Almost surely, 2^21407663872 is an apocalyptic number.

It is an amenable number.

21407663872 is an abundant number, since it is smaller than the sum of its proper divisors (27428573424).

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

21407663872 is an equidigital number, since it uses as much as digits as its factorization.

21407663872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11946264 (or 11946250 counting only the distinct ones).

The product of its (nonzero) digits is 677376, while the sum is 46.

The spelling of 21407663872 in words is "twenty-one billion, four hundred seven million, six hundred sixty-three thousand, eight hundred seventy-two".