21534389880 has 64 divisors (see below), whose sum is σ = 64761271200. Its totient is φ = 5728450560.

The previous prime is 21534389867. The next prime is 21534389897. The reversal of 21534389880 is 8898343512.

It is a congruent number.

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, 170301 + ... + 268460.

Almost surely, 2^21534389880 is an apocalyptic number.

21534389880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21534389880 is an abundant number, since it is smaller than the sum of its proper divisors (43226881320).

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

21534389880 is a wasteful number, since it uses less digits than its factorization.

21534389880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439184 (or 439180 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 51.

The spelling of 21534389880 in words is "twenty-one billion, five hundred thirty-four million, three hundred eighty-nine thousand, eight hundred eighty".