129265823 has 4 divisors (see below), whose sum is σ = 129915600. Its totient is φ = 128616048.

The previous prime is 129265733. The next prime is 129265853. The reversal of 129265823 is 328562921.

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

It is a cyclic number.

It is not a de Polignac number, because 129265823 - 2¹⁶ = 129200287 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 (129265853) 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, 324590 + ... + 324987.

It is an arithmetic number, because the mean of its divisors is an integer number (32478900).

Almost surely, 2^129265823 is an apocalyptic number.

129265823 is a deficient number, since it is larger than the sum of its proper divisors (649777).

129265823 is an equidigital number, since it uses as much as digits as its factorization.

129265823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649776.

The product of its digits is 51840, while the sum is 38.

The square root of 129265823 is about 11369.5128743495. The cubic root of 129265823 is about 505.6242621395.

The spelling of 129265823 in words is "one hundred twenty-nine million, two hundred sixty-five thousand, eight hundred twenty-three".