129023305 has 4 divisors (see below), whose sum is σ = 154827972. Its totient is φ = 103218640.

The previous prime is 129023303. The next prime is 129023317. The reversal of 129023305 is 503320921.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 35010889 + 94012416 = 5917^2 + 9696^2 .

It is not a de Polignac number, because 129023305 - 2¹ = 129023303 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 129023305.

It is not an unprimeable number, because it can be changed into a prime (129023303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12902326 + ... + 12902335.

It is an arithmetic number, because the mean of its divisors is an integer number (38706993).

Almost surely, 2^129023305 is an apocalyptic number.

It is an amenable number.

129023305 is a deficient number, since it is larger than the sum of its proper divisors (25804667).

129023305 is an equidigital number, since it uses as much as digits as its factorization.

129023305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25804666.

The product of its (nonzero) digits is 1620, while the sum is 25.

The square root of 129023305 is about 11358.8425906868. The cubic root of 129023305 is about 505.3078605130.

The spelling of 129023305 in words is "one hundred twenty-nine million, twenty-three thousand, three hundred five".