1191392879 has 2 divisors, whose sum is σ = 1191392880. Its totient is φ = 1191392878.

The previous prime is 1191392833. The next prime is 1191392911. The reversal of 1191392879 is 9782931911.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1191392879 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1191392179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 595696439 + 595696440.

It is an arithmetic number, because the mean of its divisors is an integer number (595696440).

Almost surely, 2^1191392879 is an apocalyptic number.

1191392879 is a deficient number, since it is larger than the sum of its proper divisors (1).

1191392879 is an equidigital number, since it uses as much as digits as its factorization.

1191392879 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 1191392879 is about 34516.5594896131. The cubic root of 1191392879 is about 1060.1117951983. Note that the first 3 decimals are identical.

The spelling of 1191392879 in words is "one billion, one hundred ninety-one million, three hundred ninety-two thousand, eight hundred seventy-nine".