18774857 has 2 divisors, whose sum is σ = 18774858. Its totient is φ = 18774856.

The previous prime is 18774841. The next prime is 18774859. The reversal of 18774857 is 75847781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11316496 + 7458361 = 3364^2 + 2731^2 .

It is a cyclic number.

It is not a de Polignac number, because 18774857 - 2⁴ = 18774841 is a prime.

Together with 18774859, 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 (18774859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9387428 + 9387429.

It is an arithmetic number, because the mean of its divisors is an integer number (9387429).

Almost surely, 2^18774857 is an apocalyptic number.

It is an amenable number.

18774857 is a deficient number, since it is larger than the sum of its proper divisors (1).

18774857 is an equidigital number, since it uses as much as digits as its factorization.

18774857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 439040, while the sum is 47.

The square root of 18774857 is about 4332.9963074067. The cubic root of 18774857 is about 265.7819882513.

The spelling of 18774857 in words is "eighteen million, seven hundred seventy-four thousand, eight hundred fifty-seven".