991112839 has 2 divisors, whose sum is σ = 991112840. Its totient is φ = 991112838.

The previous prime is 991112831. The next prime is 991112867. The reversal of 991112839 is 938211199.

It is a weak prime.

It is an emirp because it is prime and its reverse (938211199) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 991112839 - 2³ = 991112831 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 991112795 and 991112804.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991112831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495556419 + 495556420.

It is an arithmetic number, because the mean of its divisors is an integer number (495556420).

Almost surely, 2^991112839 is an apocalyptic number.

991112839 is a deficient number, since it is larger than the sum of its proper divisors (1).

991112839 is an equidigital number, since it uses as much as digits as its factorization.

991112839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34992, while the sum is 43.

The square root of 991112839 is about 31481.9446508630. The cubic root of 991112839 is about 997.0287936763.

The spelling of 991112839 in words is "nine hundred ninety-one million, one hundred twelve thousand, eight hundred thirty-nine".