18320957 has 4 divisors (see below), whose sum is σ = 18816156. Its totient is φ = 17825760.

The previous prime is 18320947. The next prime is 18320963. The reversal of 18320957 is 75902381.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75902381 = 199 ⋅381419.

It can be written as a sum of positive squares in 2 ways, for example, as 15202201 + 3118756 = 3899^2 + 1766^2 .

It is a cyclic number.

It is not a de Polignac number, because 18320957 - 2¹⁶ = 18255421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18320947) 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, 247544 + ... + 247617.

It is an arithmetic number, because the mean of its divisors is an integer number (4704039).

Almost surely, 2^18320957 is an apocalyptic number.

It is an amenable number.

18320957 is a deficient number, since it is larger than the sum of its proper divisors (495199).

18320957 is an equidigital number, since it uses as much as digits as its factorization.

18320957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495198.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 18320957 is about 4280.2987045299. The cubic root of 18320957 is about 263.6226482506.

The spelling of 18320957 in words is "eighteen million, three hundred twenty thousand, nine hundred fifty-seven".