129997888 has 14 divisors (see below), whose sum is σ = 257964686. Its totient is φ = 64998912.

The previous prime is 129997877. The next prime is 129997891. The reversal of 129997888 is 888799921.

It can be written as a sum of positive squares in only one way, i.e., 68029504 + 61968384 = 8248^2 + 7872^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1015545 + ... + 1015672.

It is an arithmetic number, because the mean of its divisors is an integer number (18426049).

Almost surely, 2^129997888 is an apocalyptic number.

It is an amenable number.

129997888 is a deficient number, since it is larger than the sum of its proper divisors (127966798).

129997888 is an equidigital number, since it uses as much as digits as its factorization.

129997888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2031229 (or 2031219 counting only the distinct ones).

The product of its digits is 5225472, while the sum is 61.

The square root of 129997888 is about 11401.6616332884. The cubic root of 129997888 is about 506.5769585713.

The spelling of 129997888 in words is "one hundred twenty-nine million, nine hundred ninety-seven thousand, eight hundred eighty-eight".