18471281 has 2 divisors, whose sum is σ = 18471282. Its totient is φ = 18471280.

The previous prime is 18471247. The next prime is 18471317. The reversal of 18471281 is 18217481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18318400 + 152881 = 4280^2 + 391^2 .

It is a cyclic number.

It is not a de Polignac number, because 18471281 - 2¹⁸ = 18209137 is a prime.

It is a super-2 number, since 2×18471281² = 682376443561922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18471241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9235640 + 9235641.

It is an arithmetic number, because the mean of its divisors is an integer number (9235641).

Almost surely, 2^18471281 is an apocalyptic number.

It is an amenable number.

18471281 is a deficient number, since it is larger than the sum of its proper divisors (1).

18471281 is an equidigital number, since it uses as much as digits as its factorization.

18471281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3584, while the sum is 32.

The square root of 18471281 is about 4297.8228209176. The cubic root of 18471281 is about 264.3416957900.

The spelling of 18471281 in words is "eighteen million, four hundred seventy-one thousand, two hundred eighty-one".