18810997920 has 432 divisors, whose sum is σ = 75840160032. Its totient is φ = 4208855040.

The previous prime is 18810997901. The next prime is 18810997951. The reversal of 18810997920 is 2979901881.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2673447 + ... + 2680473.

It is an arithmetic number, because the mean of its divisors is an integer number (175555926).

Almost surely, 2^18810997920 is an apocalyptic number.

18810997920 is a gapful number since it is divisible by the number (10) 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 18810997920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37920080016).

18810997920 is an abundant number, since it is smaller than the sum of its proper divisors (57029162112).

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

18810997920 is a wasteful number, since it uses less digits than its factorization.

18810997920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7085 (or 7061 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 54.

The spelling of 18810997920 in words is "eighteen billion, eight hundred ten million, nine hundred ninety-seven thousand, nine hundred twenty".