18391248 has 30 divisors (see below), whose sum is σ = 51470354. Its totient is φ = 6130368.

The previous prime is 18391213. The next prime is 18391271. The reversal of 18391248 is 84219381.

It can be written as a sum of positive squares in only one way, i.e., 18045504 + 345744 = 4248^2 + 588^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 63715 + ... + 64002.

Almost surely, 2^18391248 is an apocalyptic number.

18391248 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

18391248 is an abundant number, since it is smaller than the sum of its proper divisors (33079106).

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

18391248 is a wasteful number, since it uses less digits than its factorization.

18391248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127731 (or 127722 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 18391248 is about 4288.5018363060. The cubic root of 18391248 is about 263.9593601355.

The spelling of 18391248 in words is "eighteen million, three hundred ninety-one thousand, two hundred forty-eight".