21812371880 has 64 divisors (see below), whose sum is σ = 53063942400. Its totient is φ = 8021664000.

The previous prime is 21812371859. The next prime is 21812371897. The reversal of 21812371880 is 8817321812.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46961 + ... + 214079.

It is an arithmetic number, because the mean of its divisors is an integer number (829124100).

Almost surely, 2^21812371880 is an apocalyptic number.

21812371880 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 21812371880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26531971200).

21812371880 is an abundant number, since it is smaller than the sum of its proper divisors (31251570520).

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

21812371880 is a wasteful number, since it uses less digits than its factorization.

21812371880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167394 (or 167390 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 41.

The spelling of 21812371880 in words is "twenty-one billion, eight hundred twelve million, three hundred seventy-one thousand, eight hundred eighty".