129684240 has 240 divisors, whose sum is σ = 516716928. Its totient is φ = 29611008.

The previous prime is 129684239. The next prime is 129684257. The reversal of 129684240 is 42486921.

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a junction number, because it is equal to n+sod(n) for n = 129684195 and 129684204.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 135604 + ... + 136556.

Almost surely, 2^129684240 is an apocalyptic number.

129684240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129684240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (258358464).

129684240 is an abundant number, since it is smaller than the sum of its proper divisors (387032688).

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

129684240 is an equidigital number, since it uses as much as digits as its factorization.

129684240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 988 (or 970 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 129684240 is about 11387.8988404358. The cubic root of 129684240 is about 506.1692216794.

The spelling of 129684240 in words is "one hundred twenty-nine million, six hundred eighty-four thousand, two hundred forty".