18307649 has 4 divisors (see below), whose sum is σ = 18318336. Its totient is φ = 18296964.

The previous prime is 18307603. The next prime is 18307651. The reversal of 18307649 is 94670381.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18307649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18307669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2129 + ... + 6414.

It is an arithmetic number, because the mean of its divisors is an integer number (4579584).

Almost surely, 2^18307649 is an apocalyptic number.

It is an amenable number.

18307649 is a deficient number, since it is larger than the sum of its proper divisors (10687).

18307649 is an equidigital number, since it uses as much as digits as its factorization.

18307649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10686.

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 18307649 is about 4278.7438577227. The cubic root of 18307649 is about 263.5588026047.

The spelling of 18307649 in words is "eighteen million, three hundred seven thousand, six hundred forty-nine".