129536640 has 192 divisors, whose sum is σ = 458583840. Its totient is φ = 33675264.

The previous prime is 129536629. The next prime is 129536647. The reversal of 129536640 is 46635921.

It is a happy number.

129536640 is a `hidden beast` number, since 1 + 2 + 9 + 5 + 3 + 6 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

It is a super-2 number, since 2×129536640² = 33559482204979200, which contains 22 as substring.

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 = 129536595 and 129536604.

It is not an unprimeable number, because it can be changed into a prime (129536647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 247419 + ... + 247941.

Almost surely, 2^129536640 is an apocalyptic number.

129536640 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 129536640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (229291920).

129536640 is an abundant number, since it is smaller than the sum of its proper divisors (329047200).

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

129536640 is a wasteful number, since it uses less digits than its factorization.

129536640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 591 (or 576 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 129536640 is about 11381.4164320615. The cubic root of 129536640 is about 505.9771167663.

The spelling of 129536640 in words is "one hundred twenty-nine million, five hundred thirty-six thousand, six hundred forty".