195979879 has 2 divisors, whose sum is σ = 195979880. Its totient is φ = 195979878.

The previous prime is 195979873. The next prime is 195979907. The reversal of 195979879 is 978979591.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 195979879 - 2³ = 195979871 is a prime.

It is a super-2 number, since 2×195979879² = 76816225945709282, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 195979879.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (195979871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97989939 + 97989940.

It is an arithmetic number, because the mean of its divisors is an integer number (97989940).

Almost surely, 2^195979879 is an apocalyptic number.

195979879 is a deficient number, since it is larger than the sum of its proper divisors (1).

195979879 is an equidigital number, since it uses as much as digits as its factorization.

195979879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12859560, while the sum is 64.

The square root of 195979879 is about 13999.2813744135. The cubic root of 195979879 is about 580.8586953670.

The spelling of 195979879 in words is "one hundred ninety-five million, nine hundred seventy-nine thousand, eight hundred seventy-nine".