18609959 has 4 divisors (see below), whose sum is σ = 18618600. Its totient is φ = 18601320.

The previous prime is 18609931. The next prime is 18609973. The reversal of 18609959 is 95990681.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 18609959 - 2¹² = 18605863 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 (18609919) 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, 1817 + ... + 6365.

It is an arithmetic number, because the mean of its divisors is an integer number (4654650).

Almost surely, 2^18609959 is an apocalyptic number.

18609959 is a deficient number, since it is larger than the sum of its proper divisors (8641).

18609959 is an equidigital number, since it uses as much as digits as its factorization.

18609959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8640.

The product of its (nonzero) digits is 174960, while the sum is 47.

The square root of 18609959 is about 4313.9261699756. The cubic root of 18609959 is about 265.0015853708.

The spelling of 18609959 in words is "eighteen million, six hundred nine thousand, nine hundred fifty-nine".