129999966 has 16 divisors (see below), whose sum is σ = 263881344. Its totient is φ = 42686424.

The previous prime is 129999931. The next prime is 129999973. The reversal of 129999966 is 669999921.

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, 161290 + ... + 162093.

It is an arithmetic number, because the mean of its divisors is an integer number (16492584).

Almost surely, 2^129999966 is an apocalyptic number.

129999966 is an abundant number, since it is smaller than the sum of its proper divisors (133881378).

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

129999966 is a wasteful number, since it uses less digits than its factorization.

129999966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323455.

The product of its digits is 4251528, while the sum is 60.

The square root of 129999966 is about 11401.7527599926. The cubic root of 129999966 is about 506.5796577467.

The spelling of 129999966 in words is "one hundred twenty-nine million, nine hundred ninety-nine thousand, nine hundred sixty-six".