123012309 has 32 divisors (see below), whose sum is σ = 198762496. Its totient is φ = 66173760.

The previous prime is 123012271. The next prime is 123012313. The reversal of 123012309 is 903210321.

It is a happy number.

It is not a de Polignac number, because 123012309 - 2⁸ = 123012053 is a prime.

It is a super-2 number, since 2×123012309² = 30264056331022962, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123012319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21534 + ... + 26640.

It is an arithmetic number, because the mean of its divisors is an integer number (6211328).

Almost surely, 2^123012309 is an apocalyptic number.

It is an amenable number.

123012309 is a deficient number, since it is larger than the sum of its proper divisors (75750187).

123012309 is a wasteful number, since it uses less digits than its factorization.

123012309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5185.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 123012309 is about 11091.0914251033. The cubic root of 123012309 is about 497.3355722027.

It can be divided in two parts, 123012 and 309, that added together give a palindrome (123321).

The spelling of 123012309 in words is "one hundred twenty-three million, twelve thousand, three hundred nine".