18271240 has 64 divisors (see below), whose sum is σ = 45405360. Its totient is φ = 6574080.

The previous prime is 18271237. The next prime is 18271241. The reversal of 18271240 is 4217281.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 4088484 + 14182756 = 2022^2 + 3766^2 .

It is a super-2 number, since 2×18271240² = 667676422275200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18271241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20892 + ... + 21748.

Almost surely, 2^18271240 is an apocalyptic number.

18271240 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 18271240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22702680).

18271240 is an abundant number, since it is smaller than the sum of its proper divisors (27134120).

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

18271240 is a wasteful number, since it uses less digits than its factorization.

18271240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 922 (or 918 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 18271240 is about 4274.4871037354. The cubic root of 18271240 is about 263.3839707496.

The spelling of 18271240 in words is "eighteen million, two hundred seventy-one thousand, two hundred forty".