642104857 has 2 divisors, whose sum is σ = 642104858. Its totient is φ = 642104856.

The previous prime is 642104851. The next prime is 642104873. The reversal of 642104857 is 758401246.

642104857 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 490223881 + 151880976 = 22141^2 + 12324^2 .

It is a cyclic number.

It is not a de Polignac number, because 642104857 - 2²³ = 633716249 is a prime.

It is not a weakly prime, because it can be changed into another prime (642104851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321052428 + 321052429.

It is an arithmetic number, because the mean of its divisors is an integer number (321052429).

Almost surely, 2^642104857 is an apocalyptic number.

It is an amenable number.

642104857 is a deficient number, since it is larger than the sum of its proper divisors (1).

642104857 is an equidigital number, since it uses as much as digits as its factorization.

642104857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 53760, while the sum is 37.

The square root of 642104857 is about 25339.7880220021. The cubic root of 642104857 is about 862.7175873915.

The spelling of 642104857 in words is "six hundred forty-two million, one hundred four thousand, eight hundred fifty-seven".