18157972 has 48 divisors (see below), whose sum is σ = 39529728. Its totient is φ = 7119360.

The previous prime is 18157961. The next prime is 18157991. The reversal of 18157972 is 27975181.

It is a congruent number.

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, 17097 + ... + 18127.

It is an arithmetic number, because the mean of its divisors is an integer number (823536).

Almost surely, 2^18157972 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18157972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19764864).

18157972 is an abundant number, since it is smaller than the sum of its proper divisors (21371756).

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

18157972 is a wasteful number, since it uses less digits than its factorization.

18157972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1096 (or 1094 counting only the distinct ones).

The product of its digits is 35280, while the sum is 40.

The square root of 18157972 is about 4261.2171969990. The cubic root of 18157972 is about 262.8385810887.

The spelling of 18157972 in words is "eighteen million, one hundred fifty-seven thousand, nine hundred seventy-two".