18390290 has 32 divisors (see below), whose sum is σ = 35130240. Its totient is φ = 6912000.

The previous prime is 18390289. The next prime is 18390299. The reversal of 18390290 is 9209381.

It is a super-4 number, since 4×18390290⁴ (a number of 30 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (18390299) 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, 28370 + ... + 29010.

It is an arithmetic number, because the mean of its divisors is an integer number (1097820).

Almost surely, 2^18390290 is an apocalyptic number.

18390290 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18390290 is a deficient number, since it is larger than the sum of its proper divisors (16739950).

18390290 is a wasteful number, since it uses less digits than its factorization.

18390290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 818.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 18390290 is about 4288.3901408337. The cubic root of 18390290 is about 263.9547768420.

The spelling of 18390290 in words is "eighteen million, three hundred ninety thousand, two hundred ninety".