199442779 has 2 divisors, whose sum is σ = 199442780. Its totient is φ = 199442778.

The previous prime is 199442777. The next prime is 199442797. The reversal of 199442779 is 977244991.

Together with next prime (199442797) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199442779 - 2¹ = 199442777 is a prime.

Together with 199442777, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (199442777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99721389 + 99721390.

It is an arithmetic number, because the mean of its divisors is an integer number (99721390).

Almost surely, 2^199442779 is an apocalyptic number.

199442779 is a deficient number, since it is larger than the sum of its proper divisors (1).

199442779 is an equidigital number, since it uses as much as digits as its factorization.

199442779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1143072, while the sum is 52.

The square root of 199442779 is about 14122.4211451153. The cubic root of 199442779 is about 584.2599344457.

The spelling of 199442779 in words is "one hundred ninety-nine million, four hundred forty-two thousand, seven hundred seventy-nine".