991143229 has 2 divisors, whose sum is σ = 991143230. Its totient is φ = 991143228.

The previous prime is 991143221. The next prime is 991143239. The reversal of 991143229 is 922341199.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 784560100 + 206583129 = 28010^2 + 14373^2 .

It is a cyclic number.

It is not a de Polignac number, because 991143229 - 2³ = 991143221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 991143191 and 991143200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991143221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495571614 + 495571615.

It is an arithmetic number, because the mean of its divisors is an integer number (495571615).

Almost surely, 2^991143229 is an apocalyptic number.

It is an amenable number.

991143229 is a deficient number, since it is larger than the sum of its proper divisors (1).

991143229 is an equidigital number, since it uses as much as digits as its factorization.

991143229 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 40.

The square root of 991143229 is about 31482.4273047680. The cubic root of 991143229 is about 997.0389840382.

The spelling of 991143229 in words is "nine hundred ninety-one million, one hundred forty-three thousand, two hundred twenty-nine".