18571321 has 2 divisors, whose sum is σ = 18571322. Its totient is φ = 18571320.

The previous prime is 18571307. The next prime is 18571331. The reversal of 18571321 is 12317581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17131321 + 1440000 = 4139^2 + 1200^2 .

It is a cyclic number.

It is not a de Polignac number, because 18571321 - 2⁷ = 18571193 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18571321.

It is not a weakly prime, because it can be changed into another prime (18571331) 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 as a sum of consecutive naturals, namely, 9285660 + 9285661.

It is an arithmetic number, because the mean of its divisors is an integer number (9285661).

Almost surely, 2^18571321 is an apocalyptic number.

It is an amenable number.

18571321 is a deficient number, since it is larger than the sum of its proper divisors (1).

18571321 is an equidigital number, since it uses as much as digits as its factorization.

18571321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1680, while the sum is 28.

The square root of 18571321 is about 4309.4455559851. The cubic root of 18571321 is about 264.8180595214.

The spelling of 18571321 in words is "eighteen million, five hundred seventy-one thousand, three hundred twenty-one".