129991844 has 12 divisors (see below), whose sum is σ = 239458800. Its totient is φ = 61575048.

The previous prime is 129991831. The next prime is 129991867. The reversal of 129991844 is 448199921.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 855134 + ... + 855285.

It is an arithmetic number, because the mean of its divisors is an integer number (19954900).

Almost surely, 2^129991844 is an apocalyptic number.

It is an amenable number.

129991844 is a deficient number, since it is larger than the sum of its proper divisors (109466956).

129991844 is a wasteful number, since it uses less digits than its factorization.

129991844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1710442 (or 1710440 counting only the distinct ones).

The product of its digits is 186624, while the sum is 47.

The square root of 129991844 is about 11401.3965811211. The cubic root of 129991844 is about 506.5691076781.

The spelling of 129991844 in words is "one hundred twenty-nine million, nine hundred ninety-one thousand, eight hundred forty-four".