18671249 has 2 divisors, whose sum is σ = 18671250. Its totient is φ = 18671248.

The previous prime is 18671227. The next prime is 18671251. The reversal of 18671249 is 94217681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14440000 + 4231249 = 3800^2 + 2057^2 .

It is an emirp because it is prime and its reverse (94217681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18671249 - 2²⁴ = 1894033 is a prime.

Together with 18671251, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18671449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9335624 + 9335625.

It is an arithmetic number, because the mean of its divisors is an integer number (9335625).

Almost surely, 2^18671249 is an apocalyptic number.

It is an amenable number.

18671249 is a deficient number, since it is larger than the sum of its proper divisors (1).

18671249 is an equidigital number, since it uses as much as digits as its factorization.

18671249 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24192, while the sum is 38.

The square root of 18671249 is about 4321.0240684356. The cubic root of 18671249 is about 265.2921851392.

The spelling of 18671249 in words is "eighteen million, six hundred seventy-one thousand, two hundred forty-nine".