18309361 has 4 divisors (see below), whose sum is σ = 20924992. Its totient is φ = 15693732.

The previous prime is 18309341. The next prime is 18309371. The reversal of 18309361 is 16390381.

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 18309361 - 2⁷ = 18309233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18309341) 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, 1307805 + ... + 1307818.

It is an arithmetic number, because the mean of its divisors is an integer number (5231248).

Almost surely, 2^18309361 is an apocalyptic number.

It is an amenable number.

18309361 is a deficient number, since it is larger than the sum of its proper divisors (2615631).

18309361 is an equidigital number, since it uses as much as digits as its factorization.

18309361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2615630.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 18309361 is about 4278.9439117614. The cubic root of 18309361 is about 263.5670177248.

The spelling of 18309361 in words is "eighteen million, three hundred nine thousand, three hundred sixty-one".