21056051072 has 64 divisors (see below), whose sum is σ = 48918588000. Its totient is φ = 9024003072.

The previous prime is 21056051041. The next prime is 21056051119. The reversal of 21056051072 is 27015065012.

It is a tau number, because it is divible by the number of its divisors (64).

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, 195893 + ... + 283700.

Almost surely, 2^21056051072 is an apocalyptic number.

It is an amenable number.

21056051072 is an abundant number, since it is smaller than the sum of its proper divisors (27862536928).

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

21056051072 is an frugal number, since it uses more digits than its factorization.

21056051072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479628 (or 479602 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 29.

The spelling of 21056051072 in words is "twenty-one billion, fifty-six million, fifty-one thousand, seventy-two".