999931 has 2 divisors, whose sum is σ = 999932. Its totient is φ = 999930.

The previous prime is 999917. The next prime is 999953. The reversal of 999931 is 139999.

It is a weak prime.

It is an emirp because it is prime and its reverse (139999) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-999931 is a prime.

It is a super-2 number, since 2×999931² = 1999724009522, which contains 22 as substring.

It is a nialpdrome in base 10.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 999931.

It is not a weakly prime, because it can be changed into another prime (999961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499965 + 499966.

It is an arithmetic number, because the mean of its divisors is an integer number (499966).

2⁹⁹⁹⁹³¹ is an apocalyptic number.

999931 is a deficient number, since it is larger than the sum of its proper divisors (1).

999931 is an equidigital number, since it uses as much as digits as its factorization.

999931 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19683, while the sum is 40.

The square root of 999931 is about 999.9654994049. The cubic root of 999931 is about 99.9976999471.

The spelling of 999931 in words is "nine hundred ninety-nine thousand, nine hundred thirty-one".