129081405600 has 756 divisors, whose sum is σ = 549722467854. Its totient is φ = 29497789440.

The previous prime is 129081405559. The next prime is 129081405601. The reversal of 129081405600 is 6504180921.

129081405600 is a `hidden beast` number, since 1 + 2 + 9 + 0 + 8 + 1 + 40 + 5 + 600 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 50414619024 + 78666786576 = 224532^2 + 280476^2 .

It is a tau number, because it is divible by the number of its divisors (756).

It is a super-2 number, since 2×129081405600² (a number of 23 digits) contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (129081405601) by changing a digit.

It is a polite number, since it can be written in 125 ways as a sum of consecutive naturals, for example, 28574542 + ... + 28579058.

Almost surely, 2^129081405600 is an apocalyptic number.

129081405600 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 129081405600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (274861233927).

129081405600 is an abundant number, since it is smaller than the sum of its proper divisors (420641062254).

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

129081405600 is an equidigital number, since it uses as much as digits as its factorization.

129081405600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4569 (or 4534 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The spelling of 129081405600 in words is "one hundred twenty-nine billion, eighty-one million, four hundred five thousand, six hundred".