123229991 has 24 divisors (see below), whose sum is σ = 142277040. Its totient is φ = 106064640.

The previous prime is 123229979. The next prime is 123230011. The reversal of 123229991 is 199922321.

It is a de Polignac number, because none of the positive numbers 2^k-123229991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123229291) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 310205 + ... + 310601.

It is an arithmetic number, because the mean of its divisors is an integer number (5928210).

Almost surely, 2^123229991 is an apocalyptic number.

123229991 is a deficient number, since it is larger than the sum of its proper divisors (19047049).

123229991 is a wasteful number, since it uses less digits than its factorization.

123229991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 495 (or 464 counting only the distinct ones).

The product of its digits is 17496, while the sum is 38.

The square root of 123229991 is about 11100.9004589718. The cubic root of 123229991 is about 497.6287602211.

The spelling of 123229991 in words is "one hundred twenty-three million, two hundred twenty-nine thousand, nine hundred ninety-one".