129278868 has 24 divisors (see below), whose sum is σ = 312053280. Its totient is φ = 41606880.

The previous prime is 129278857. The next prime is 129278873. The reversal of 129278868 is 868872921.

It is a happy number.

It is a super-2 number, since 2×129278868² = 33426051422722848, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 129278868.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 185398 + ... + 186093.

It is an arithmetic number, because the mean of its divisors is an integer number (13002220).

Almost surely, 2^129278868 is an apocalyptic number.

It is an amenable number.

129278868 is an abundant number, since it is smaller than the sum of its proper divisors (182774412).

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

129278868 is a wasteful number, since it uses less digits than its factorization.

129278868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 371527 (or 371525 counting only the distinct ones).

The product of its digits is 774144, while the sum is 51.

The square root of 129278868 is about 11370.0865432063. The cubic root of 129278868 is about 505.6412701067.

The spelling of 129278868 in words is "one hundred twenty-nine million, two hundred seventy-eight thousand, eight hundred sixty-eight".