129905685 has 48 divisors (see below), whose sum is σ = 277140864. Its totient is φ = 54815616.

The previous prime is 129905683. The next prime is 129905689. The reversal of 129905685 is 586509921.

It is not a de Polignac number, because 129905685 - 2¹ = 129905683 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

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 129905685.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129905683) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11767 + ... + 19956.

It is an arithmetic number, because the mean of its divisors is an integer number (5773768).

Almost surely, 2^129905685 is an apocalyptic number.

129905685 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

129905685 is an abundant number, since it is smaller than the sum of its proper divisors (147235179).

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

129905685 is a wasteful number, since it uses less digits than its factorization.

129905685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31754 (or 31751 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 45.

The square root of 129905685 is about 11397.6175142001. The cubic root of 129905685 is about 506.4571644137.

The spelling of 129905685 in words is "one hundred twenty-nine million, nine hundred five thousand, six hundred eighty-five".