18909365 has 4 divisors (see below), whose sum is σ = 22691244. Its totient is φ = 15127488.

The previous prime is 18909353. The next prime is 18909377. The reversal of 18909365 is 56390981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56390981 = 137 ⋅411613.

It is an interprime number because it is at equal distance from previous prime (18909353) and next prime (18909377).

It can be written as a sum of positive squares in 2 ways, for example, as 3243601 + 15665764 = 1801^2 + 3958^2 .

It is a cyclic number.

It is not a de Polignac number, because 18909365 - 2¹⁶ = 18843829 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1890932 + ... + 1890941.

It is an arithmetic number, because the mean of its divisors is an integer number (5672811).

Almost surely, 2^18909365 is an apocalyptic number.

It is an amenable number.

18909365 is a deficient number, since it is larger than the sum of its proper divisors (3781879).

18909365 is an equidigital number, since it uses as much as digits as its factorization.

18909365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3781878.

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

The square root of 18909365 is about 4348.4899677934. The cubic root of 18909365 is about 266.4151891363.

The spelling of 18909365 in words is "eighteen million, nine hundred nine thousand, three hundred sixty-five".