18774247 has 2 divisors, whose sum is σ = 18774248. Its totient is φ = 18774246.

The previous prime is 18774211. The next prime is 18774263. The reversal of 18774247 is 74247781.

It is a strong prime.

It is an emirp because it is prime and its reverse (74247781) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18774247 is a prime.

It is equal to p_1197598 and since 18774247 and 1197598 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18774347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9387123 + 9387124.

It is an arithmetic number, because the mean of its divisors is an integer number (9387124).

Almost surely, 2^18774247 is an apocalyptic number.

18774247 is a deficient number, since it is larger than the sum of its proper divisors (1).

18774247 is an equidigital number, since it uses as much as digits as its factorization.

18774247 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 87808, while the sum is 40.

The square root of 18774247 is about 4332.9259167449. The cubic root of 18774247 is about 265.7791097781.

The spelling of 18774247 in words is "eighteen million, seven hundred seventy-four thousand, two hundred forty-seven".