18122240 has 40 divisors (see below), whose sum is σ = 43457040. Its totient is φ = 7247872.

The previous prime is 18122207. The next prime is 18122243. The reversal of 18122240 is 4222181.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18122243) 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, 980 + ... + 6099.

It is an arithmetic number, because the mean of its divisors is an integer number (1086426).

Almost surely, 2^18122240 is an apocalyptic number.

18122240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18122240 is an abundant number, since it is smaller than the sum of its proper divisors (25334800).

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

18122240 is an frugal number, since it uses more digits than its factorization.

18122240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7102 (or 7086 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 18122240 is about 4257.0224335796. The cubic root of 18122240 is about 262.6660597041. Note that the first 3 decimals are identical.

The spelling of 18122240 in words is "eighteen million, one hundred twenty-two thousand, two hundred forty".