18673321 has 2 divisors, whose sum is σ = 18673322. Its totient is φ = 18673320.

The previous prime is 18673313. The next prime is 18673339. The reversal of 18673321 is 12337681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15210000 + 3463321 = 3900^2 + 1861^2 .

It is a cyclic number.

It is not a de Polignac number, because 18673321 - 2³ = 18673313 is a prime.

It is equal to p_1191577 and since 18673321 and 1191577 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (18673621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9336660 + 9336661.

It is an arithmetic number, because the mean of its divisors is an integer number (9336661).

Almost surely, 2^18673321 is an apocalyptic number.

It is an amenable number.

18673321 is a deficient number, since it is larger than the sum of its proper divisors (1).

18673321 is an equidigital number, since it uses as much as digits as its factorization.

18673321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 31.

The square root of 18673321 is about 4321.2638197638. The cubic root of 18673321 is about 265.3019981780.

The spelling of 18673321 in words is "eighteen million, six hundred seventy-three thousand, three hundred twenty-one".