18307645 has 4 divisors (see below), whose sum is σ = 21969180. Its totient is φ = 14646112.

The previous prime is 18307603. The next prime is 18307651. The reversal of 18307645 is 54670381.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54670381 = 3463 ⋅15787.

It can be written as a sum of positive squares in 2 ways, for example, as 12766329 + 5541316 = 3573^2 + 2354^2 .

It is a cyclic number.

It is not a de Polignac number, because 18307645 - 2¹¹ = 18305597 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18307645.

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, 1830760 + ... + 1830769.

It is an arithmetic number, because the mean of its divisors is an integer number (5492295).

Almost surely, 2^18307645 is an apocalyptic number.

It is an amenable number.

18307645 is a deficient number, since it is larger than the sum of its proper divisors (3661535).

18307645 is an equidigital number, since it uses as much as digits as its factorization.

18307645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3661534.

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 18307645 is about 4278.7433902958. The cubic root of 18307645 is about 263.5587834099.

The spelling of 18307645 in words is "eighteen million, three hundred seven thousand, six hundred forty-five".