199999427 has 2 divisors, whose sum is σ = 199999428. Its totient is φ = 199999426.

The previous prime is 199999409. The next prime is 199999447. The reversal of 199999427 is 724999991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199999427 - 2²² = 195805123 is a prime.

It is not a weakly prime, because it can be changed into another prime (199999447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99999713 + 99999714.

It is an arithmetic number, because the mean of its divisors is an integer number (99999714).

Almost surely, 2^199999427 is an apocalyptic number.

199999427 is a deficient number, since it is larger than the sum of its proper divisors (1).

199999427 is an equidigital number, since it uses as much as digits as its factorization.

199999427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3306744, while the sum is 59.

The square root of 199999427 is about 14142.1153651072. The cubic root of 199999427 is about 584.8029891547.

The spelling of 199999427 in words is "one hundred ninety-nine million, nine hundred ninety-nine thousand, four hundred twenty-seven".