129857868 has 72 divisors (see below), whose sum is σ = 378862848. Its totient is φ = 36734688.

The previous prime is 129857857. The next prime is 129857873. The reversal of 129857868 is 868758921.

129857868 is a `hidden beast` number, since 1 + 2 + 9 + 8 + 578 + 68 = 666.

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 23 ways as a sum of consecutive naturals, for example, 23455 + ... + 28457.

It is an arithmetic number, because the mean of its divisors is an integer number (5261984).

Almost surely, 2^129857868 is an apocalyptic number.

129857868 is a gapful number since it is divisible by the number (18) 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 129857868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (189431424).

129857868 is an abundant number, since it is smaller than the sum of its proper divisors (249004980).

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

129857868 is a wasteful number, since it uses less digits than its factorization.

129857868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5123 (or 5118 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 54.

The square root of 129857868 is about 11395.5196458959. The cubic root of 129857868 is about 506.3950161605.

The spelling of 129857868 in words is "one hundred twenty-nine million, eight hundred fifty-seven thousand, eight hundred sixty-eight".