79911869 has 2 divisors, whose sum is σ = 79911870. Its totient is φ = 79911868.

The previous prime is 79911857. The next prime is 79911877. The reversal of 79911869 is 96811997.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79887844 + 24025 = 8938^2 + 155^2 .

It is an emirp because it is prime and its reverse (96811997) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 79911869 - 2⁸ = 79911613 is a prime.

It is a super-2 number, since 2×79911869² = 12771813614146322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79911569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39955934 + 39955935.

It is an arithmetic number, because the mean of its divisors is an integer number (39955935).

Almost surely, 2^79911869 is an apocalyptic number.

It is an amenable number.

79911869 is a deficient number, since it is larger than the sum of its proper divisors (1).

79911869 is an equidigital number, since it uses as much as digits as its factorization.

79911869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 244944, while the sum is 50.

The square root of 79911869 is about 8939.3438797263. The cubic root of 79911869 is about 430.7286527981.

The spelling of 79911869 in words is "seventy-nine million, nine hundred eleven thousand, eight hundred sixty-nine".