668154857 has 2 divisors, whose sum is σ = 668154858. Its totient is φ = 668154856.

The previous prime is 668154847. The next prime is 668154947. The reversal of 668154857 is 758451866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 500685376 + 167469481 = 22376^2 + 12941^2 .

It is a cyclic number.

It is not a de Polignac number, because 668154857 - 2⁴ = 668154841 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (668154827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334077428 + 334077429.

It is an arithmetic number, because the mean of its divisors is an integer number (334077429).

Almost surely, 2^668154857 is an apocalyptic number.

It is an amenable number.

668154857 is a deficient number, since it is larger than the sum of its proper divisors (1).

668154857 is an equidigital number, since it uses as much as digits as its factorization.

668154857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1612800, while the sum is 50.

The square root of 668154857 is about 25848.6915916454. The cubic root of 668154857 is about 874.2300086548.

The spelling of 668154857 in words is "six hundred sixty-eight million, one hundred fifty-four thousand, eight hundred fifty-seven".