21387304080 has 60 divisors (see below), whose sum is σ = 71825698620. Its totient is φ = 5703280896.

The previous prime is 21387304069. The next prime is 21387304109. The reversal of 21387304080 is 8040378312.

21387304080 is a `hidden beast` number, since 213 + 8 + 7 + 30 + 408 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 3272297616 + 18115006464 = 57204^2 + 134592^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 14851575 + ... + 14853014.

It is an arithmetic number, because the mean of its divisors is an integer number (1197094977).

Almost surely, 2^21387304080 is an apocalyptic number.

21387304080 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21387304080 is an abundant number, since it is smaller than the sum of its proper divisors (50438394540).

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

21387304080 is a wasteful number, since it uses less digits than its factorization.

21387304080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29704608 (or 29704599 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The spelling of 21387304080 in words is "twenty-one billion, three hundred eighty-seven million, three hundred four thousand, eighty".