199945679 has 2 divisors, whose sum is σ = 199945680. Its totient is φ = 199945678.

The previous prime is 199945673. The next prime is 199945699. The reversal of 199945679 is 976549991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199945679 - 2⁴ = 199945663 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199945673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99972839 + 99972840.

It is an arithmetic number, because the mean of its divisors is an integer number (99972840).

Almost surely, 2^199945679 is an apocalyptic number.

199945679 is a deficient number, since it is larger than the sum of its proper divisors (1).

199945679 is an equidigital number, since it uses as much as digits as its factorization.

199945679 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5511240, while the sum is 59.

The square root of 199945679 is about 14140.2149559333. The cubic root of 199945679 is about 584.7505976593.

The spelling of 199945679 in words is "one hundred ninety-nine million, nine hundred forty-five thousand, six hundred seventy-nine".