21507280704 has 756 divisors, whose sum is σ = 81010317024. Its totient is φ = 5638284288.

The previous prime is 21507280607. The next prime is 21507280721. The reversal of 21507280704 is 40708270512.

21507280704 is a `hidden beast` number, since 2 + 1 + 507 + 2 + 80 + 70 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (756).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 128786029 + ... + 128786195.

It is an arithmetic number, because the mean of its divisors is an integer number (107156504).

Almost surely, 2^21507280704 is an apocalyptic number.

21507280704 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21507280704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40505158512).

21507280704 is an abundant number, since it is smaller than the sum of its proper divisors (59503036320).

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

21507280704 is a wasteful number, since it uses less digits than its factorization.

21507280704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234 (or 192 counting only the distinct ones).

The product of its (nonzero) digits is 31360, while the sum is 36.

The spelling of 21507280704 in words is "twenty-one billion, five hundred seven million, two hundred eighty thousand, seven hundred four".