999331 has 2 divisors, whose sum is σ = 999332.
Its totient is φ = 999330.
The previous prime is 999329. The next prime is 999359. The reversal of 999331 is 133999.
It is a happy number.
It is a weak prime.
It is an emirp because it is prime and its reverse (133999) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 999331 - 21 = 999329 is a prime.
It is a super-2 number, since 2×9993312 = 1997324895122, which contains 22 as substring.
Together with 999329, it forms a pair of twin primes.
999331 is a lucky number.
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 999331.
It is not a weakly prime, because it can be changed into another prime (999371) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499665 + 499666.
It is an arithmetic number, because the mean of its divisors is an integer number (499666).
2999331 is an apocalyptic number.
999331 is a deficient number, since it is larger than the sum of its proper divisors (1).
999331 is an equidigital number, since it uses as much as digits as its factorization.
999331 is an evil number, because the sum of its binary digits is even.
The product of its digits is 6561, while the sum is 34.
The square root of 999331 is about 999.6654440362.
The cubic root of 999331 is about 99.9776950253.
The spelling of 999331 in words is "nine hundred ninety-nine thousand, three hundred thirty-one".