18219240 has 192 divisors, whose sum is σ = 67813200. Its totient is φ = 4202496.

The previous prime is 18219203. The next prime is 18219251. The reversal of 18219240 is 4291281.

It can be written as a sum of positive squares in 8 ways, for example, as 11655396 + 6563844 = 3414^2 + 2562^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 79446 + ... + 79674.

Almost surely, 2^18219240 is an apocalyptic number.

18219240 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 18219240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33906600).

18219240 is an abundant number, since it is smaller than the sum of its proper divisors (49593960).

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

18219240 is a wasteful number, since it uses less digits than its factorization.

18219240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276 (or 269 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 18219240 is about 4268.4001686815. The cubic root of 18219240 is about 263.1338694979.

The spelling of 18219240 in words is "eighteen million, two hundred nineteen thousand, two hundred forty".