18909617 has 4 divisors (see below), whose sum is σ = 19904880. Its totient is φ = 17914356.

The previous prime is 18909601. The next prime is 18909619. The reversal of 18909617 is 71690981.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18909617 - 2⁴ = 18909601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18909619) 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, 497603 + ... + 497640.

It is an arithmetic number, because the mean of its divisors is an integer number (4976220).

Almost surely, 2^18909617 is an apocalyptic number.

It is an amenable number.

18909617 is a deficient number, since it is larger than the sum of its proper divisors (995263).

18909617 is an equidigital number, since it uses as much as digits as its factorization.

18909617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 995262.

The product of its (nonzero) digits is 27216, while the sum is 41.

The square root of 18909617 is about 4348.5189432725. The cubic root of 18909617 is about 266.4163726121.

The spelling of 18909617 in words is "eighteen million, nine hundred nine thousand, six hundred seventeen".