18238536 has 72 divisors (see below), whose sum is σ = 50940630. Its totient is φ = 5894784.

The previous prime is 18238523. The next prime is 18238553. The reversal of 18238536 is 63583281.

It can be written as a sum of positive squares in only one way, i.e., 14976900 + 3261636 = 3870^2 + 1806^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 18238536.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 133060 + ... + 133196.

Almost surely, 2^18238536 is an apocalyptic number.

18238536 is the 2466-th octagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18238536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25470315).

18238536 is an abundant number, since it is smaller than the sum of its proper divisors (32702094).

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

18238536 is a wasteful number, since it uses less digits than its factorization.

18238536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235 (or 185 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 18238536 is about 4270.6599021697. The cubic root of 18238536 is about 263.2267317632.

The spelling of 18238536 in words is "eighteen million, two hundred thirty-eight thousand, five hundred thirty-six".