18505920 has 112 divisors (see below), whose sum is σ = 60460128. Its totient is φ = 4792320.

The previous prime is 18505919. The next prime is 18505931. The reversal of 18505920 is 2950581.

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 35260 + ... + 35780.

Almost surely, 2^18505920 is an apocalyptic number.

18505920 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 18505920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30230064).

18505920 is an abundant number, since it is smaller than the sum of its proper divisors (41954208).

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

18505920 is a wasteful number, since it uses less digits than its factorization.

18505920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 578 (or 568 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 30.

The square root of 18505920 is about 4301.8507644966. The cubic root of 18505920 is about 264.5068316793.

The spelling of 18505920 in words is "eighteen million, five hundred five thousand, nine hundred twenty".