21988780120 has 32 divisors (see below), whose sum is σ = 49481093520. Its totient is φ = 8794385280.

The previous prime is 21988780109. The next prime is 21988780133. The reversal of 21988780120 is 2108788912.

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, 326899 + ... + 388381.

Almost surely, 2^21988780120 is an apocalyptic number.

21988780120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21988780120 is an abundant number, since it is smaller than the sum of its proper divisors (27492313400).

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

21988780120 is a wasteful number, since it uses less digits than its factorization.

21988780120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70435 (or 70431 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 46.

The spelling of 21988780120 in words is "twenty-one billion, nine hundred eighty-eight million, seven hundred eighty thousand, one hundred twenty".