129520805 has 8 divisors (see below), whose sum is σ = 155488032. Its totient is φ = 103574608.

The previous prime is 129520801. The next prime is 129520813. The reversal of 129520805 is 508025921.

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 129520805 - 2² = 129520801 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 (129520801) 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, 16454 + ... + 23016.

It is an arithmetic number, because the mean of its divisors is an integer number (19436004).

Almost surely, 2^129520805 is an apocalyptic number.

It is an amenable number.

129520805 is a deficient number, since it is larger than the sum of its proper divisors (25967227).

129520805 is an equidigital number, since it uses as much as digits as its factorization.

129520805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10515.

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 129520805 is about 11380.7207592490. The cubic root of 129520805 is about 505.9564984708.

The spelling of 129520805 in words is "one hundred twenty-nine million, five hundred twenty thousand, eight hundred five".