18487990 has 16 divisors (see below), whose sum is σ = 33907248. Its totient is φ = 7255456.

The previous prime is 18487951. The next prime is 18488011. The reversal of 18487990 is 9978481.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 18487990.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16912 + ... + 17971.

It is an arithmetic number, because the mean of its divisors is an integer number (2119203).

Almost surely, 2^18487990 is an apocalyptic number.

18487990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18487990 is a deficient number, since it is larger than the sum of its proper divisors (15419258).

18487990 is a wasteful number, since it uses less digits than its factorization.

18487990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34943.

The product of its (nonzero) digits is 145152, while the sum is 46.

The square root of 18487990 is about 4299.7662727176. The cubic root of 18487990 is about 264.4213790243.

The spelling of 18487990 in words is "eighteen million, four hundred eighty-seven thousand, nine hundred ninety".