199857157 has 2 divisors, whose sum is σ = 199857158. Its totient is φ = 199857156.

The previous prime is 199857121. The next prime is 199857169. The reversal of 199857157 is 751758991.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 165739876 + 34117281 = 12874^2 + 5841^2 .

It is a cyclic number.

It is not a de Polignac number, because 199857157 - 2¹⁹ = 199332869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199857187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99928578 + 99928579.

It is an arithmetic number, because the mean of its divisors is an integer number (99928579).

Almost surely, 2^199857157 is an apocalyptic number.

It is an amenable number.

199857157 is a deficient number, since it is larger than the sum of its proper divisors (1).

199857157 is an equidigital number, since it uses as much as digits as its factorization.

199857157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 793800, while the sum is 52.

The square root of 199857157 is about 14137.0844589682. The cubic root of 199857157 is about 584.6642893286.

The spelling of 199857157 in words is "one hundred ninety-nine million, eight hundred fifty-seven thousand, one hundred fifty-seven".