18572321 has 2 divisors, whose sum is σ = 18572322. Its totient is φ = 18572320.

The previous prime is 18572287. The next prime is 18572363. The reversal of 18572321 is 12327581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18181696 + 390625 = 4264^2 + 625^2 .

It is a cyclic number.

It is not a de Polignac number, because 18572321 - 2¹⁸ = 18310177 is a prime.

It is a super-2 number, since 2×18572321² = 689862214654082, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18572371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9286160 + 9286161.

It is an arithmetic number, because the mean of its divisors is an integer number (9286161).

Almost surely, 2^18572321 is an apocalyptic number.

It is an amenable number.

18572321 is a deficient number, since it is larger than the sum of its proper divisors (1).

18572321 is an equidigital number, since it uses as much as digits as its factorization.

18572321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3360, while the sum is 29.

The square root of 18572321 is about 4309.5615786295. The cubic root of 18572321 is about 264.8228126082.

The spelling of 18572321 in words is "eighteen million, five hundred seventy-two thousand, three hundred twenty-one".