18486728 has 32 divisors (see below), whose sum is σ = 37611000. Its totient is φ = 8467968.

The previous prime is 18486691. The next prime is 18486763. The reversal of 18486728 is 82768481.

It can be written as a sum of positive squares in 4 ways, for example, as 8988004 + 9498724 = 2998^2 + 3082^2 .

It is a super-2 number, since 2×18486728² = 683518224291968, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14900 + ... + 16092.

Almost surely, 2^18486728 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 18486728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18805500).

18486728 is an abundant number, since it is smaller than the sum of its proper divisors (19124272).

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

18486728 is a wasteful number, since it uses less digits than its factorization.

18486728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1361 (or 1357 counting only the distinct ones).

The product of its digits is 172032, while the sum is 44.

The square root of 18486728 is about 4299.6195180504. The cubic root of 18486728 is about 264.4153623729.

The spelling of 18486728 in words is "eighteen million, four hundred eighty-six thousand, seven hundred twenty-eight".