129261305 has 4 divisors (see below), whose sum is σ = 155113572. Its totient is φ = 103409040.

The previous prime is 129261287. The next prime is 129261347. The reversal of 129261305 is 503162921.

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 14600041 + 114661264 = 3821^2 + 10708^2 .

It is not a de Polignac number, because 129261305 - 2¹⁶ = 129195769 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12926126 + ... + 12926135.

It is an arithmetic number, because the mean of its divisors is an integer number (38778393).

Almost surely, 2^129261305 is an apocalyptic number.

It is an amenable number.

129261305 is a deficient number, since it is larger than the sum of its proper divisors (25852267).

129261305 is an equidigital number, since it uses as much as digits as its factorization.

129261305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25852266.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 129261305 is about 11369.3141833622. The cubic root of 129261305 is about 505.6183713402.

The spelling of 129261305 in words is "one hundred twenty-nine million, two hundred sixty-one thousand, three hundred five".