999389 has 2 divisors, whose sum is σ = 999390. Its totient is φ = 999388.

The previous prime is 999377. The next prime is 999431. The reversal of 999389 is 983999.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 532900 + 466489 = 730^2 + 683^2 .

It is a cyclic number.

It is not a de Polignac number, because 999389 - 2⁸ = 999133 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499694 + 499695.

It is an arithmetic number, because the mean of its divisors is an integer number (499695).

2⁹⁹⁹³⁸⁹ is an apocalyptic number.

It is an amenable number.

999389 is a deficient number, since it is larger than the sum of its proper divisors (1).

999389 is an equidigital number, since it uses as much as digits as its factorization.

999389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 157464, while the sum is 47.

The square root of 999389 is about 999.6944533206. The cubic root of 999389 is about 99.9796291839.

The spelling of 999389 in words is "nine hundred ninety-nine thousand, three hundred eighty-nine".