18450979920 has 480 divisors, whose sum is σ = 67479609600. Its totient is φ = 4501094400.

The previous prime is 18450979873. The next prime is 18450979949. The reversal of 18450979920 is 2997905481.

18450979920 is a `hidden beast` number, since 18 + 450 + 97 + 9 + 92 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 122191845 + ... + 122191995.

It is an arithmetic number, because the mean of its divisors is an integer number (140582520).

Almost surely, 2^18450979920 is an apocalyptic number.

18450979920 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 18450979920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33739804800).

18450979920 is an abundant number, since it is smaller than the sum of its proper divisors (49028629680).

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

18450979920 is a wasteful number, since it uses less digits than its factorization.

18450979920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 403 (or 394 counting only the distinct ones).

The product of its (nonzero) digits is 1632960, while the sum is 54.

The spelling of 18450979920 in words is "eighteen billion, four hundred fifty million, nine hundred seventy-nine thousand, nine hundred twenty".