129778740 has 384 divisors, whose sum is σ = 526848000. Its totient is φ = 25754112.

The previous prime is 129778729. The next prime is 129778769. The reversal of 129778740 is 47877921.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 933591 + ... + 933729.

It is an arithmetic number, because the mean of its divisors is an integer number (1372000).

Almost surely, 2^129778740 is an apocalyptic number.

129778740 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 129778740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263424000).

129778740 is an abundant number, since it is smaller than the sum of its proper divisors (397069260).

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

129778740 is a wasteful number, since it uses less digits than its factorization.

129778740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196 (or 188 counting only the distinct ones).

The product of its (nonzero) digits is 197568, while the sum is 45.

The square root of 129778740 is about 11392.0472260257. The cubic root of 129778740 is about 506.2921391535.

The spelling of 129778740 in words is "one hundred twenty-nine million, seven hundred seventy-eight thousand, seven hundred forty".