129775561344 has 768 divisors, whose sum is σ = 460327795200. Its totient is φ = 35876597760.

The previous prime is 129775561309. The next prime is 129775561369. The reversal of 129775561344 is 443165577921.

129775561344 is a `hidden beast` number, since 1 + 2 + 9 + 7 + 75 + 561 + 3 + 4 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 725003047 + ... + 725003225.

It is an arithmetic number, because the mean of its divisors is an integer number (599385150).

Almost surely, 2^129775561344 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 129775561344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (230163897600).

129775561344 is an abundant number, since it is smaller than the sum of its proper divisors (330552233856).

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

129775561344 is a wasteful number, since it uses less digits than its factorization.

129775561344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395 (or 371 counting only the distinct ones).

The product of its digits is 6350400, while the sum is 54.

It can be divided in two parts, 12977 and 5561344, that added together give a square (5574321 = 2361²).

The spelling of 129775561344 in words is "one hundred twenty-nine billion, seven hundred seventy-five million, five hundred sixty-one thousand, three hundred forty-four".