18660857 has 2 divisors, whose sum is σ = 18660858. Its totient is φ = 18660856.

The previous prime is 18660847. The next prime is 18660893. The reversal of 18660857 is 75806681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11999296 + 6661561 = 3464^2 + 2581^2 .

It is a cyclic number.

It is not a de Polignac number, because 18660857 - 2⁴ = 18660841 is a prime.

It is not a weakly prime, because it can be changed into another prime (18660847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9330428 + 9330429.

It is an arithmetic number, because the mean of its divisors is an integer number (9330429).

Almost surely, 2^18660857 is an apocalyptic number.

It is an amenable number.

18660857 is a deficient number, since it is larger than the sum of its proper divisors (1).

18660857 is an equidigital number, since it uses as much as digits as its factorization.

18660857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 80640, while the sum is 41.

The square root of 18660857 is about 4319.8214083455. The cubic root of 18660857 is about 265.2429574375.

The spelling of 18660857 in words is "eighteen million, six hundred sixty thousand, eight hundred fifty-seven".