21787534080 has 972 divisors, whose sum is σ = 88928618688. Its totient is φ = 4916920320.

The previous prime is 21787534073. The next prime is 21787534123. The reversal of 21787534080 is 8043578712.

21787534080 is a `hidden beast` number, since 2 + 178 + 75 + 3 + 408 + 0 = 666.

It is a super-2 number, since 2×21787534080² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 702823665 + ... + 702823695.

Almost surely, 2^21787534080 is an apocalyptic number.

21787534080 is a gapful number since it is divisible by the number (20) 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 21787534080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44464309344).

21787534080 is an abundant number, since it is smaller than the sum of its proper divisors (67141084608).

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

21787534080 is a wasteful number, since it uses less digits than its factorization.

21787534080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 73 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 45.

The spelling of 21787534080 in words is "twenty-one billion, seven hundred eighty-seven million, five hundred thirty-four thousand, eighty".