18436240 has 20 divisors (see below), whose sum is σ = 42864444. Its totient is φ = 7374464.

The previous prime is 18436193. The next prime is 18436241. The reversal of 18436240 is 4263481.

It can be written as a sum of positive squares in 2 ways, for example, as 11943936 + 6492304 = 3456^2 + 2548^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 18436199 and 18436208.

It is not an unprimeable number, because it can be changed into a prime (18436241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115147 + ... + 115306.

Almost surely, 2^18436240 is an apocalyptic number.

18436240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18436240 is an abundant number, since it is smaller than the sum of its proper divisors (24428204).

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

18436240 is a wasteful number, since it uses less digits than its factorization.

18436240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230466 (or 230460 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 18436240 is about 4293.7442867502. The cubic root of 18436240 is about 264.1744332365.

The spelling of 18436240 in words is "eighteen million, four hundred thirty-six thousand, two hundred forty".