199999957 has 2 divisors, whose sum is σ = 199999958. Its totient is φ = 199999956.

The previous prime is 199999949. The next prime is 199999963. The reversal of 199999957 is 759999991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 194017041 + 5982916 = 13929^2 + 2446^2 .

It is a cyclic number.

It is not a de Polignac number, because 199999957 - 2³ = 199999949 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 199999892 and 199999901.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199999057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99999978 + 99999979.

It is an arithmetic number, because the mean of its divisors is an integer number (99999979).

Almost surely, 2^199999957 is an apocalyptic number.

It is an amenable number.

199999957 is a deficient number, since it is larger than the sum of its proper divisors (1).

199999957 is an equidigital number, since it uses as much as digits as its factorization.

199999957 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18600435, while the sum is 67.

The square root of 199999957 is about 14142.1341034513. The cubic root of 199999957 is about 584.8035057316.

It can be divided in two parts, 19999995 and 7, that added together give a palindrome (20000002).

The spelling of 199999957 in words is "one hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred fifty-seven".