18399065 has 4 divisors (see below), whose sum is σ = 22078884. Its totient is φ = 14719248.

The previous prime is 18399047. The next prime is 18399067. The reversal of 18399065 is 56099381.

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 14462809 + 3936256 = 3803^2 + 1984^2 .

It is a cyclic number.

It is not a de Polignac number, because 18399065 - 2⁶ = 18399001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18399067) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1839902 + ... + 1839911.

It is an arithmetic number, because the mean of its divisors is an integer number (5519721).

Almost surely, 2^18399065 is an apocalyptic number.

It is an amenable number.

18399065 is a deficient number, since it is larger than the sum of its proper divisors (3679819).

18399065 is an equidigital number, since it uses as much as digits as its factorization.

18399065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3679818.

The product of its (nonzero) digits is 58320, while the sum is 41.

The square root of 18399065 is about 4289.4131300214. The cubic root of 18399065 is about 263.9967525236.

The spelling of 18399065 in words is "eighteen million, three hundred ninety-nine thousand, sixty-five".