18990799 has 4 divisors (see below), whose sum is σ = 19003264. Its totient is φ = 18978336.

The previous prime is 18990793. The next prime is 18990809. The reversal of 18990799 is 99709981.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18990799 - 2⁵ = 18990767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18990793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3567 + ... + 7120.

It is an arithmetic number, because the mean of its divisors is an integer number (4750816).

Almost surely, 2^18990799 is an apocalyptic number.

18990799 is a deficient number, since it is larger than the sum of its proper divisors (12465).

18990799 is a wasteful number, since it uses less digits than its factorization.

18990799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12464.

The product of its (nonzero) digits is 367416, while the sum is 52.

The square root of 18990799 is about 4357.8433886499. The cubic root of 18990799 is about 266.7970842970.

It can be divided in two parts, 189 and 90799, that multiplied together give a triangular number (17161011 = T₅₈₅₈).

The spelling of 18990799 in words is "eighteen million, nine hundred ninety thousand, seven hundred ninety-nine".