129661280 has 48 divisors (see below), whose sum is σ = 350088480. Its totient is φ = 44454912.

The previous prime is 129661271. The next prime is 129661289. The reversal of 129661280 is 82166921.

129661280 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (129661271) and next prime (129661289).

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 129661280.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129661289) 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, 56765 + ... + 59004.

It is an arithmetic number, because the mean of its divisors is an integer number (7293510).

Almost surely, 2^129661280 is an apocalyptic number.

129661280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129661280 is an abundant number, since it is smaller than the sum of its proper divisors (220427200).

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

129661280 is a wasteful number, since it uses less digits than its factorization.

129661280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115791 (or 115783 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 129661280 is about 11386.8907081784. The cubic root of 129661280 is about 506.1393482699.

The spelling of 129661280 in words is "one hundred twenty-nine million, six hundred sixty-one thousand, two hundred eighty".