129618225 has 135 divisors (see below), whose sum is σ = 275882299. Its totient is φ = 60112800.

The previous prime is 129618169. The next prime is 129618227. The reversal of 129618225 is 522816921.

The square root of 129618225 is 11385.

It is a perfect power (a square), and thus also a powerful number.

129618225 is a `hidden beast` number, since 12 + 9 + 618 + 2 + 25 = 666.

It can be written as a sum of positive squares in only one way, i.e., 46662561 + 82955664 = 6831^2 + 9108^2 .

It is a tau number, because it is divible by the number of its divisors (135).

It is not a de Polignac number, because 129618225 - 2¹⁵ = 129585457 is a prime.

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

Its product of digits (17280) is a multiple of the sum of its prime factors (90).

It is a self number, because there is not a number n which added to its sum of digits gives 129618225.

It is not an unprimeable number, because it can be changed into a prime (129618227) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 5635564 + ... + 5635586.

Almost surely, 2^129618225 is an apocalyptic number.

129618225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

129618225 is the 11385-th square number.

129618225 is the 5693-rd centered octagonal number.

It is an amenable number.

129618225 is an abundant number, since it is smaller than the sum of its proper divisors (146264074).

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

129618225 is a wasteful number, since it uses less digits than its factorization.

129618225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90 (or 42 counting only the distinct ones).

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

The cubic root of 129618225 is about 506.0833196129.

Multiplying 129618225 by its sum of digits (36), we get a square (4666256100 = 68310²).

It can be divided in two parts, 1296 and 18225, that multiplied together give a square (23619600 = 4860²).

The spelling of 129618225 in words is "one hundred twenty-nine million, six hundred eighteen thousand, two hundred twenty-five".