21877115988 has 192 divisors, whose sum is σ = 66301562880. Its totient is φ = 5456360448.

The previous prime is 21877115959. The next prime is 21877115993. The reversal of 21877115988 is 88951177812.

It is a super-2 number, since 2×21877115988² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2230431 + ... + 2240217.

It is an arithmetic number, because the mean of its divisors is an integer number (345320640).

Almost surely, 2^21877115988 is an apocalyptic number.

21877115988 is a gapful number since it is divisible by the number (28) 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 21877115988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33150781440).

21877115988 is an abundant number, since it is smaller than the sum of its proper divisors (44424446892).

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

21877115988 is a wasteful number, since it uses less digits than its factorization.

21877115988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9926 (or 9924 counting only the distinct ones).

The product of its digits is 2257920, while the sum is 57.

The spelling of 21877115988 in words is "twenty-one billion, eight hundred seventy-seven million, one hundred fifteen thousand, nine hundred eighty-eight".