18927990 has 48 divisors (see below), whose sum is σ = 51807600. Its totient is φ = 4781376.

The previous prime is 18927989. The next prime is 18928003. The reversal of 18927990 is 9972981.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3825 + ... + 7244.

It is an arithmetic number, because the mean of its divisors is an integer number (1079325).

Almost surely, 2^18927990 is an apocalyptic number.

18927990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18927990 is an abundant number, since it is smaller than the sum of its proper divisors (32879610).

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

18927990 is a wasteful number, since it uses less digits than its factorization.

18927990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11101 (or 11098 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 18927990 is about 4350.6309887188. The cubic root of 18927990 is about 266.5026300184.

The spelling of 18927990 in words is "eighteen million, nine hundred twenty-seven thousand, nine hundred ninety".