18204240 has 80 divisors (see below), whose sum is σ = 57067776. Its totient is φ = 4800000.

The previous prime is 18204233. The next prime is 18204253. The reversal of 18204240 is 4240281.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23865 + ... + 24615.

Almost surely, 2^18204240 is an apocalyptic number.

18204240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18204240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28533888).

18204240 is an abundant number, since it is smaller than the sum of its proper divisors (38863536).

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

18204240 is a wasteful number, since it uses less digits than its factorization.

18204240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 868 (or 862 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

The square root of 18204240 is about 4266.6427082661. The cubic root of 18204240 is about 263.0616364860.

The spelling of 18204240 in words is "eighteen million, two hundred four thousand, two hundred forty".