199861279 has 2 divisors, whose sum is σ = 199861280. Its totient is φ = 199861278.

The previous prime is 199861267. The next prime is 199861349. The reversal of 199861279 is 972168991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199861279 - 2²⁷ = 65643551 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199861579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99930639 + 99930640.

It is an arithmetic number, because the mean of its divisors is an integer number (99930640).

Almost surely, 2^199861279 is an apocalyptic number.

199861279 is a deficient number, since it is larger than the sum of its proper divisors (1).

199861279 is an equidigital number, since it uses as much as digits as its factorization.

199861279 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 52.

The square root of 199861279 is about 14137.2302449950. The cubic root of 199861279 is about 584.6683088154.

The spelling of 199861279 in words is "one hundred ninety-nine million, eight hundred sixty-one thousand, two hundred seventy-nine".