166403857 has 2 divisors, whose sum is σ = 166403858. Its totient is φ = 166403856.

The previous prime is 166403849. The next prime is 166403917. The reversal of 166403857 is 758304661.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164762896 + 1640961 = 12836^2 + 1281^2 .

It is an emirp because it is prime and its reverse (758304661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166403857 - 2³ = 166403849 is a prime.

It is not a weakly prime, because it can be changed into another prime (166403357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83201928 + 83201929.

It is an arithmetic number, because the mean of its divisors is an integer number (83201929).

Almost surely, 2^166403857 is an apocalyptic number.

It is an amenable number.

166403857 is a deficient number, since it is larger than the sum of its proper divisors (1).

166403857 is an equidigital number, since it uses as much as digits as its factorization.

166403857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 40.

The square root of 166403857 is about 12899.7618970274. The cubic root of 166403857 is about 550.0317965089.

The spelling of 166403857 in words is "one hundred sixty-six million, four hundred three thousand, eight hundred fifty-seven".