18568321 has 2 divisors, whose sum is σ = 18568322. Its totient is φ = 18568320.

The previous prime is 18568309. The next prime is 18568343. The reversal of 18568321 is 12386581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17313921 + 1254400 = 4161^2 + 1120^2 .

It is a cyclic number.

It is not a de Polignac number, because 18568321 - 2²³ = 10179713 is a prime.

It is not a weakly prime, because it can be changed into another prime (18568351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9284160 + 9284161.

It is an arithmetic number, because the mean of its divisors is an integer number (9284161).

Almost surely, 2^18568321 is an apocalyptic number.

It is an amenable number.

18568321 is a deficient number, since it is larger than the sum of its proper divisors (1).

18568321 is an equidigital number, since it uses as much as digits as its factorization.

18568321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 34.

The square root of 18568321 is about 4309.0974693084. The cubic root of 18568321 is about 264.8037992369.

The spelling of 18568321 in words is "eighteen million, five hundred sixty-eight thousand, three hundred twenty-one".