123309999 has 16 divisors (see below), whose sum is σ = 186570240. Its totient is φ = 80456760.

The previous prime is 123309913. The next prime is 123310003. The reversal of 123309999 is 999903321.

It is not a de Polignac number, because 123309999 - 2⁷ = 123309871 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123309299) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47317 + ... + 49854.

It is an arithmetic number, because the mean of its divisors is an integer number (11660640).

Almost surely, 2^123309999 is an apocalyptic number.

123309999 is a deficient number, since it is larger than the sum of its proper divisors (63260241).

123309999 is an equidigital number, since it uses as much as digits as its factorization.

123309999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97227 (or 97221 counting only the distinct ones).

The product of its (nonzero) digits is 118098, while the sum is 45.

The square root of 123309999 is about 11104.5035458592. The cubic root of 123309999 is about 497.7364333291.

The spelling of 123309999 in words is "one hundred twenty-three million, three hundred nine thousand, nine hundred ninety-nine".