18438436 has 27 divisors (see below), whose sum is σ = 34358961. Its totient is φ = 8656704.

The previous prime is 18438391. The next prime is 18438437. The reversal of 18438436 is 63483481.

The square root of 18438436 is 4294.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 324900 + 18113536 = 570^2 + 4256^2 .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18438395 and 18438404.

It is not an unprimeable number, because it can be changed into a prime (18438437) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 163116 + ... + 163228.

Almost surely, 2^18438436 is an apocalyptic number.

18438436 is the 4294-th square number.

It is an amenable number.

18438436 is a deficient number, since it is larger than the sum of its proper divisors (15920525).

18438436 is a wasteful number, since it uses less digits than its factorization.

18438436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268 (or 134 counting only the distinct ones).

The product of its digits is 55296, while the sum is 37.

The cubic root of 18438436 is about 264.1849217096.

The spelling of 18438436 in words is "eighteen million, four hundred thirty-eight thousand, four hundred thirty-six".