18157980 has 72 divisors (see below), whose sum is σ = 52326288. Its totient is φ = 4704512.

The previous prime is 18157961. The next prime is 18157991. The reversal of 18157980 is 8975181.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 132472 + ... + 132608.

It is an arithmetic number, because the mean of its divisors is an integer number (726754).

Almost surely, 2^18157980 is an apocalyptic number.

18157980 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 18157980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26163144).

18157980 is an abundant number, since it is smaller than the sum of its proper divisors (34168308).

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

18157980 is a wasteful number, since it uses less digits than its factorization.

18157980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243 (or 194 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 39.

The square root of 18157980 is about 4261.2181356978. The cubic root of 18157980 is about 262.8386196890.

The spelling of 18157980 in words is "eighteen million, one hundred fifty-seven thousand, nine hundred eighty".