199657243 has 2 divisors, whose sum is σ = 199657244. Its totient is φ = 199657242.

The previous prime is 199657223. The next prime is 199657303. The reversal of 199657243 is 342756991.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (342756991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 199657243 - 2²¹ = 197560091 is a prime.

It is a super-2 number, since 2×199657243² = 79726029364722098, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 199657193 and 199657202.

It is not a weakly prime, because it can be changed into another prime (199657223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99828621 + 99828622.

It is an arithmetic number, because the mean of its divisors is an integer number (99828622).

Almost surely, 2^199657243 is an apocalyptic number.

199657243 is a deficient number, since it is larger than the sum of its proper divisors (1).

199657243 is an equidigital number, since it uses as much as digits as its factorization.

199657243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 408240, while the sum is 46.

The square root of 199657243 is about 14130.0121372913. The cubic root of 199657243 is about 584.4692807666.

The spelling of 199657243 in words is "one hundred ninety-nine million, six hundred fifty-seven thousand, two hundred forty-three".