21887178872 has 32 divisors (see below), whose sum is σ = 44204160000. Its totient is φ = 10099741824.

The previous prime is 21887178869. The next prime is 21887178881. The reversal of 21887178872 is 27887178812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 579593 + ... + 616199.

It is an arithmetic number, because the mean of its divisors is an integer number (1381380000).

Almost surely, 2^21887178872 is an apocalyptic number.

It is an amenable number.

21887178872 is an abundant number, since it is smaller than the sum of its proper divisors (22316981128).

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

21887178872 is a wasteful number, since it uses less digits than its factorization.

21887178872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42375 (or 42371 counting only the distinct ones).

The product of its digits is 5619712, while the sum is 59.

The spelling of 21887178872 in words is "twenty-one billion, eight hundred eighty-seven million, one hundred seventy-eight thousand, eight hundred seventy-two".