1231000399 has 2 divisors, whose sum is σ = 1231000400. Its totient is φ = 1231000398.

The previous prime is 1231000373. The next prime is 1231000469. The reversal of 1231000399 is 9930001321.

It is a weak prime.

It is an emirp because it is prime and its reverse (9930001321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1231000399 - 2⁷ = 1231000271 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1231000349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615500199 + 615500200.

It is an arithmetic number, because the mean of its divisors is an integer number (615500200).

Almost surely, 2^1231000399 is an apocalyptic number.

1231000399 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231000399 is an equidigital number, since it uses as much as digits as its factorization.

1231000399 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1458, while the sum is 28.

The square root of 1231000399 is about 35085.6152717891. The cubic root of 1231000399 is about 1071.7316703170.

The spelling of 1231000399 in words is "one billion, two hundred thirty-one million, three hundred ninety-nine", and thus it is an aban number.