18438280 has 32 divisors (see below), whose sum is σ = 47413440. Its totient is φ = 6321600.

The previous prime is 18438263. The next prime is 18438283. The reversal of 18438280 is 8283481.

It is not an unprimeable number, because it can be changed into a prime (18438283) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32646 + ... + 33205.

It is an arithmetic number, because the mean of its divisors is an integer number (1481670).

Almost surely, 2^18438280 is an apocalyptic number.

18438280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18438280 is an abundant number, since it is smaller than the sum of its proper divisors (28975160).

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

18438280 is a wasteful number, since it uses less digits than its factorization.

18438280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65869 (or 65865 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 34.

The square root of 18438280 is about 4293.9818350803. The cubic root of 18438280 is about 264.1841766543.

The spelling of 18438280 in words is "eighteen million, four hundred thirty-eight thousand, two hundred eighty".