18919790 has 16 divisors (see below), whose sum is σ = 34235568. Its totient is φ = 7527936.

The previous prime is 18919757. The next prime is 18919807. The reversal of 18919790 is 9791981.

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 7 ways as a sum of consecutive naturals, for example, 2972 + ... + 6831.

It is an arithmetic number, because the mean of its divisors is an integer number (2139723).

Almost surely, 2^18919790 is an apocalyptic number.

18919790 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18919790 is a deficient number, since it is larger than the sum of its proper divisors (15315778).

18919790 is a wasteful number, since it uses less digits than its factorization.

18919790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10003.

The product of its (nonzero) digits is 40824, while the sum is 44.

The square root of 18919790 is about 4349.6884945936. The cubic root of 18919790 is about 266.4641396272.

The spelling of 18919790 in words is "eighteen million, nine hundred nineteen thousand, seven hundred ninety".