999191959 has 2 divisors, whose sum is σ = 999191960. Its totient is φ = 999191958.

The previous prime is 999191957. The next prime is 999192107. The reversal of 999191959 is 959191999.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 999191959 - 2¹ = 999191957 is a prime.

Together with 999191957, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 999191897 and 999191906.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999191951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499595979 + 499595980.

It is an arithmetic number, because the mean of its divisors is an integer number (499595980).

Almost surely, 2^999191959 is an apocalyptic number.

999191959 is a deficient number, since it is larger than the sum of its proper divisors (1).

999191959 is an equidigital number, since it uses as much as digits as its factorization.

999191959 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2657205, while the sum is 61.

The square root of 999191959 is about 31609.9977696931. The cubic root of 999191959 is about 999.7305804196.

The spelling of 999191959 in words is "nine hundred ninety-nine million, one hundred ninety-one thousand, nine hundred fifty-nine".