18936990 has 48 divisors (see below), whose sum is σ = 51066288. Its totient is φ = 5049216.

The previous prime is 18936979. The next prime is 18936991. The reversal of 18936990 is 9963981.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18936991) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1467 + ... + 6326.

It is an arithmetic number, because the mean of its divisors is an integer number (1063881).

Almost surely, 2^18936990 is an apocalyptic number.

18936990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18936990 is an abundant number, since it is smaller than the sum of its proper divisors (32129298).

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

18936990 is an equidigital number, since it uses as much as digits as its factorization.

18936990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7815 (or 7803 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 45.

The square root of 18936990 is about 4351.6651985188. The cubic root of 18936990 is about 266.5448627755.

The spelling of 18936990 in words is "eighteen million, nine hundred thirty-six thousand, nine hundred ninety".