18989965 has 4 divisors (see below), whose sum is σ = 22787964. Its totient is φ = 15191968.

The previous prime is 18989959. The next prime is 18990017. The reversal of 18989965 is 56998981.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13089924 + 5900041 = 3618^2 + 2429^2 .

It is a cyclic number.

It is not a de Polignac number, because 18989965 - 2⁵ = 18989933 is a prime.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 1898992 + ... + 1899001.

It is an arithmetic number, because the mean of its divisors is an integer number (5696991).

Almost surely, 2^18989965 is an apocalyptic number.

It is an amenable number.

18989965 is a deficient number, since it is larger than the sum of its proper divisors (3797999).

18989965 is an equidigital number, since it uses as much as digits as its factorization.

18989965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3797998.

The product of its digits is 1399680, while the sum is 55.

The square root of 18989965 is about 4357.7476980661. The cubic root of 18989965 is about 266.7931786859.

The spelling of 18989965 in words is "eighteen million, nine hundred eighty-nine thousand, nine hundred sixty-five".