199799579849 has 2 divisors, whose sum is σ = 199799579850. Its totient is φ = 199799579848.

The previous prime is 199799579843. The next prime is 199799579893. The reversal of 199799579849 is 948975997991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 151940142025 + 47859437824 = 389795^2 + 218768^2 .

It is a cyclic number.

It is not a de Polignac number, because 199799579849 - 2¹² = 199799575753 is a prime.

It is not a weakly prime, because it can be changed into another prime (199799579843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99899789924 + 99899789925.

It is an arithmetic number, because the mean of its divisors is an integer number (99899789925).

Almost surely, 2^199799579849 is an apocalyptic number.

It is an amenable number.

199799579849 is a deficient number, since it is larger than the sum of its proper divisors (1).

199799579849 is an equidigital number, since it uses as much as digits as its factorization.

199799579849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4166497440, while the sum is 86.

The spelling of 199799579849 in words is "one hundred ninety-nine billion, seven hundred ninety-nine million, five hundred seventy-nine thousand, eight hundred forty-nine".