129142278 has 72 divisors (see below), whose sum is σ = 305721000. Its totient is φ = 39287808.

The previous prime is 129142271. The next prime is 129142331. The reversal of 129142278 is 872241921.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129142271) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 287398 + ... + 287846.

It is an arithmetic number, because the mean of its divisors is an integer number (4246125).

Almost surely, 2^129142278 is an apocalyptic number.

129142278 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 129142278, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (152860500).

129142278 is an abundant number, since it is smaller than the sum of its proper divisors (176578722).

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

129142278 is a wasteful number, since it uses less digits than its factorization.

129142278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 534 (or 502 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 129142278 is about 11364.0784052205. The cubic root of 129142278 is about 505.4631283881.

The spelling of 129142278 in words is "one hundred twenty-nine million, one hundred forty-two thousand, two hundred seventy-eight".