999999131 has 2 divisors, whose sum is σ = 999999132. Its totient is φ = 999999130.

The previous prime is 999999113. The next prime is 999999137. The reversal of 999999131 is 131999999.

Together with previous prime (999999113) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 999999131 - 2⁶ = 999999067 is a prime.

It is a super-2 number, since 2×999999131² = 1999996524001510322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (999999137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499999565 + 499999566.

It is an arithmetic number, because the mean of its divisors is an integer number (499999566).

Almost surely, 2^999999131 is an apocalyptic number.

999999131 is a deficient number, since it is larger than the sum of its proper divisors (1).

999999131 is an equidigital number, since it uses as much as digits as its factorization.

999999131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1594323, while the sum is 59.

The square root of 999999131 is about 31622.7628615844. The cubic root of 999999131 is about 999.9997103332. Note that the first 3 decimals are identical.

The spelling of 999999131 in words is "nine hundred ninety-nine million, nine hundred ninety-nine thousand, one hundred thirty-one".