999989231 has 2 divisors, whose sum is σ = 999989232. Its totient is φ = 999989230.

The previous prime is 999989219. The next prime is 999989257. The reversal of 999989231 is 132989999.

It is a weak prime.

It is an emirp because it is prime and its reverse (132989999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999989231 - 2¹⁴ = 999972847 is a prime.

It is a super-2 number, since 2×999989231² = 1999956924231942722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999989201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499994615 + 499994616.

It is an arithmetic number, because the mean of its divisors is an integer number (499994616).

Almost surely, 2^999989231 is an apocalyptic number.

999989231 is a deficient number, since it is larger than the sum of its proper divisors (1).

999989231 is an equidigital number, since it uses as much as digits as its factorization.

999989231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2834352, while the sum is 59.

The square root of 999989231 is about 31622.6063283848. The cubic root of 999989231 is about 999.9964103204.

The spelling of 999989231 in words is "nine hundred ninety-nine million, nine hundred eighty-nine thousand, two hundred thirty-one".