129166668 has 72 divisors (see below), whose sum is σ = 336672336. Its totient is φ = 41731200.

The previous prime is 129166657. The next prime is 129166673. The reversal of 129166668 is 866661921.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 279958 + ... + 280418.

Almost surely, 2^129166668 is an apocalyptic number.

129166668 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 129166668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (168336168).

129166668 is an abundant number, since it is smaller than the sum of its proper divisors (207505668).

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

129166668 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (129166667) it forms a Ruth-Aaron pair, since the sum of their prime factors is the same (695).

129166668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 695 (or 690 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 129166668 is about 11365.1514728137. The cubic root of 129166668 is about 505.4949472209.

The spelling of 129166668 in words is "one hundred twenty-nine million, one hundred sixty-six thousand, six hundred sixty-eight".