129972780 has 144 divisors (see below), whose sum is σ = 466240320. Its totient is φ = 28675584.

The previous prime is 129972763. The next prime is 129972833. The reversal of 129972780 is 87279921.

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

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 47 ways as a sum of consecutive naturals, for example, 34762 + ... + 38318.

It is an arithmetic number, because the mean of its divisors is an integer number (3237780).

Almost surely, 2^129972780 is an apocalyptic number.

129972780 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 129972780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (233120160).

129972780 is an abundant number, since it is smaller than the sum of its proper divisors (336267540).

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

129972780 is a wasteful number, since it uses less digits than its factorization.

129972780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3608 (or 3603 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 45.

The square root of 129972780 is about 11400.5605125362. The cubic root of 129972780 is about 506.5443427767.

The spelling of 129972780 in words is "one hundred twenty-nine million, nine hundred seventy-two thousand, seven hundred eighty".