129261825 has 120 divisors (see below), whose sum is σ = 298879680. Its totient is φ = 53654400.

The previous prime is 129261823. The next prime is 129261857. The reversal of 129261825 is 528162921.

129261825 is a `hidden beast` number, since 12 + 9 + 2 + 618 + 25 = 666.

It is not a de Polignac number, because 129261825 - 2¹ = 129261823 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 129261825.

It is not an unprimeable number, because it can be changed into a prime (129261823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 155511 + ... + 156339.

It is an arithmetic number, because the mean of its divisors is an integer number (2490664).

Almost surely, 2^129261825 is an apocalyptic number.

129261825 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

129261825 is an abundant number, since it is smaller than the sum of its proper divisors (169617855).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

129261825 is a wasteful number, since it uses less digits than its factorization.

129261825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 869 (or 855 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 129261825 is about 11369.3370519129. The cubic root of 129261825 is about 505.6190493498.

The spelling of 129261825 in words is "one hundred twenty-nine million, two hundred sixty-one thousand, eight hundred twenty-five".