18231872 has 28 divisors (see below), whose sum is σ = 36513516. Its totient is φ = 9031680.

The previous prime is 18231859. The next prime is 18231881. The reversal of 18231872 is 27813281.

It can be written as a sum of positive squares in 2 ways, for example, as 118336 + 18113536 = 344^2 + 4256^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

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, 5972 + ... + 8492.

Almost surely, 2^18231872 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 18231872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18256758).

18231872 is an abundant number, since it is smaller than the sum of its proper divisors (18281644).

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

18231872 is a wasteful number, since it uses less digits than its factorization.

18231872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2646 (or 2636 counting only the distinct ones).

The product of its digits is 5376, while the sum is 32.

The square root of 18231872 is about 4269.8796235960. The cubic root of 18231872 is about 263.1946685789.

The spelling of 18231872 in words is "eighteen million, two hundred thirty-one thousand, eight hundred seventy-two".