129213684 has 48 divisors (see below), whose sum is σ = 337592640. Its totient is φ = 42737760.

The previous prime is 129213683. The next prime is 129213691. The reversal of 129213684 is 486312921.

129213684 is a `hidden beast` number, since 1 + 292 + 1 + 368 + 4 = 666.

It is a super-2 number, since 2×129213684² = 33392352265703712, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129213683) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9582 + ... + 18714.

It is an arithmetic number, because the mean of its divisors is an integer number (7033180).

Almost surely, 2^129213684 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129213684, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (168796320).

129213684 is an abundant number, since it is smaller than the sum of its proper divisors (208378956).

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

129213684 is a wasteful number, since it uses less digits than its factorization.

129213684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9277 (or 9269 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 129213684 is about 11367.2197128410. The cubic root of 129213684 is about 505.5562722975.

The spelling of 129213684 in words is "one hundred twenty-nine million, two hundred thirteen thousand, six hundred eighty-four".