129055261 has 2 divisors, whose sum is σ = 129055262. Its totient is φ = 129055260.

The previous prime is 129055253. The next prime is 129055271. The reversal of 129055261 is 162550921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 113103225 + 15952036 = 10635^2 + 3994^2 .

It is a cyclic number.

It is not a de Polignac number, because 129055261 - 2³ = 129055253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129055271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64527630 + 64527631.

It is an arithmetic number, because the mean of its divisors is an integer number (64527631).

Almost surely, 2^129055261 is an apocalyptic number.

It is an amenable number.

129055261 is a deficient number, since it is larger than the sum of its proper divisors (1).

129055261 is an equidigital number, since it uses as much as digits as its factorization.

129055261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 129055261 is about 11360.2491609999. The cubic root of 129055261 is about 505.3495746438.

The spelling of 129055261 in words is "one hundred twenty-nine million, fifty-five thousand, two hundred sixty-one".