18720140 has 12 divisors (see below), whose sum is σ = 39312336. Its totient is φ = 7488048.

The previous prime is 18720083. The next prime is 18720173. The reversal of 18720140 is 4102781.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 467984 + ... + 468023.

It is an arithmetic number, because the mean of its divisors is an integer number (3276028).

Almost surely, 2^18720140 is an apocalyptic number.

18720140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18720140 is an abundant number, since it is smaller than the sum of its proper divisors (20592196).

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

18720140 is a wasteful number, since it uses less digits than its factorization.

18720140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 936016 (or 936014 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 18720140 is about 4326.6777092823. The cubic root of 18720140 is about 265.5235407667.

The spelling of 18720140 in words is "eighteen million, seven hundred twenty thousand, one hundred forty".