123969809 has 8 divisors (see below), whose sum is σ = 130665960. Its totient is φ = 117435136.

The previous prime is 123969799. The next prime is 123969821. The reversal of 123969809 is 908969321.

It can be written as a sum of positive squares in 4 ways, for example, as 77088400 + 46881409 = 8780^2 + 6847^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 123969809 - 2¹⁶ = 123904273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123969829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38792 + ... + 41865.

It is an arithmetic number, because the mean of its divisors is an integer number (16333245).

Almost surely, 2^123969809 is an apocalyptic number.

It is an amenable number.

123969809 is a deficient number, since it is larger than the sum of its proper divisors (6696151).

123969809 is an equidigital number, since it uses as much as digits as its factorization.

123969809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80739.

The product of its (nonzero) digits is 209952, while the sum is 47.

The square root of 123969809 is about 11134.1730272167. The cubic root of 123969809 is about 498.6226211391.

The spelling of 123969809 in words is "one hundred twenty-three million, nine hundred sixty-nine thousand, eight hundred nine".