18990305 has 8 divisors (see below), whose sum is σ = 23318592. Its totient is φ = 14838768.

The previous prime is 18990277. The next prime is 18990311. The reversal of 18990305 is 50309981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18990305 is a prime.

It is a Duffinian 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, 43949 + ... + 44378.

It is an arithmetic number, because the mean of its divisors is an integer number (2914824).

Almost surely, 2^18990305 is an apocalyptic number.

It is an amenable number.

18990305 is a deficient number, since it is larger than the sum of its proper divisors (4328287).

18990305 is an equidigital number, since it uses as much as digits as its factorization.

18990305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88375.

The product of its (nonzero) digits is 9720, while the sum is 35.

The square root of 18990305 is about 4357.7867088695. The cubic root of 18990305 is about 266.7947709153.

The spelling of 18990305 in words is "eighteen million, nine hundred ninety thousand, three hundred five".