21987175080 has 256 divisors, whose sum is σ = 76638078720. Its totient is φ = 4997431296.

The previous prime is 21987175039. The next prime is 21987175087. The reversal of 21987175080 is 8057178912.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21987175087) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1397739 + ... + 1413381.

It is an arithmetic number, because the mean of its divisors is an integer number (299367495).

Almost surely, 2^21987175080 is an apocalyptic number.

21987175080 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 21987175080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38319039360).

21987175080 is an abundant number, since it is smaller than the sum of its proper divisors (54650903640).

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

21987175080 is a wasteful number, since it uses less digits than its factorization.

21987175080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15740 (or 15736 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 48.

The spelling of 21987175080 in words is "twenty-one billion, nine hundred eighty-seven million, one hundred seventy-five thousand, eighty".