129956736 has 128 divisors (see below), whose sum is σ = 424972800. Its totient is φ = 34265088.

The previous prime is 129956719. The next prime is 129956741. The reversal of 129956736 is 637659921.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33085 + ... + 36803.

It is an arithmetic number, because the mean of its divisors is an integer number (3320100).

Almost surely, 2^129956736 is an apocalyptic number.

129956736 is a gapful number since it is divisible by the number (16) 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 129956736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (212486400).

129956736 is an abundant number, since it is smaller than the sum of its proper divisors (295016064).

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

129956736 is a wasteful number, since it uses less digits than its factorization.

129956736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3756 (or 3744 counting only the distinct ones).

The product of its digits is 612360, while the sum is 48.

The square root of 129956736 is about 11399.8568412064. The cubic root of 129956736 is about 506.5234990999.

The spelling of 129956736 in words is "one hundred twenty-nine million, nine hundred fifty-six thousand, seven hundred thirty-six".