18920857 has 2 divisors, whose sum is σ = 18920858. Its totient is φ = 18920856.

The previous prime is 18920849. The next prime is 18920873. The reversal of 18920857 is 75802981.

18920857 is nontrivially palindromic in base 11.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18913801 + 7056 = 4349^2 + 84^2 .

It is a cyclic number.

It is not a de Polignac number, because 18920857 - 2³ = 18920849 is a prime.

It is a super-2 number, since 2×18920857² = 715997659228898, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18920807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9460428 + 9460429.

It is an arithmetic number, because the mean of its divisors is an integer number (9460429).

Almost surely, 2^18920857 is an apocalyptic number.

It is an amenable number.

18920857 is a deficient number, since it is larger than the sum of its proper divisors (1).

18920857 is an equidigital number, since it uses as much as digits as its factorization.

18920857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 18920857 is about 4349.8111453257. The cubic root of 18920857 is about 266.4691487013.

The spelling of 18920857 in words is "eighteen million, nine hundred twenty thousand, eight hundred fifty-seven".