18386240 has 28 divisors (see below), whose sum is σ = 43782996. Its totient is φ = 7354368.

The previous prime is 18386219. The next prime is 18386273. The reversal of 18386240 is 4268381.

It can be written as a sum of positive squares in 2 ways, for example, as 10137856 + 8248384 = 3184^2 + 2872^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 18386197 and 18386206.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28409 + ... + 29048.

Almost surely, 2^18386240 is an apocalyptic number.

18386240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18386240 is an abundant number, since it is smaller than the sum of its proper divisors (25396756).

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

18386240 is an equidigital number, since it uses as much as digits as its factorization.

18386240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57474 (or 57464 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 18386240 is about 4287.9179096620. The cubic root of 18386240 is about 263.9353989469.

The spelling of 18386240 in words is "eighteen million, three hundred eighty-six thousand, two hundred forty".