999931393 has 2 divisors, whose sum is σ = 999931394. Its totient is φ = 999931392.

The previous prime is 999931391. The next prime is 999931399. The reversal of 999931393 is 393139999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 642267649 + 357663744 = 25343^2 + 18912^2 .

It is a cyclic number.

It is not a de Polignac number, because 999931393 - 2¹ = 999931391 is a prime.

Together with 999931391, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (999931391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499965696 + 499965697.

It is an arithmetic number, because the mean of its divisors is an integer number (499965697).

Almost surely, 2^999931393 is an apocalyptic number.

It is an amenable number.

999931393 is a deficient number, since it is larger than the sum of its proper divisors (1).

999931393 is an equidigital number, since it uses as much as digits as its factorization.

999931393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1594323, while the sum is 55.

The square root of 999931393 is about 31621.6918111603. The cubic root of 999931393 is about 999.9771304770.

The spelling of 999931393 in words is "nine hundred ninety-nine million, nine hundred thirty-one thousand, three hundred ninety-three".