18363440 has 80 divisors (see below), whose sum is σ = 44836416. Its totient is φ = 6988800.

The previous prime is 18363403. The next prime is 18363469. The reversal of 18363440 is 4436381.

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

It is a super-3 number, since 3×18363440³ (a number of 23 digits) contains 333 as substring.

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, 258605 + ... + 258675.

Almost surely, 2^18363440 is an apocalyptic number.

18363440 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 18363440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22418208).

18363440 is an abundant number, since it is smaller than the sum of its proper divisors (26472976).

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

18363440 is a wasteful number, since it uses less digits than its factorization.

18363440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198 (or 192 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 29.

The square root of 18363440 is about 4285.2584519490. The cubic root of 18363440 is about 263.8262554379.

The spelling of 18363440 in words is "eighteen million, three hundred sixty-three thousand, four hundred forty".