128531996 has 24 divisors (see below), whose sum is σ = 232621200. Its totient is φ = 62105472.

The previous prime is 128531993. The next prime is 128532013. The reversal of 128531996 is 699135821.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128531993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9680 + ... + 18728.

It is an arithmetic number, because the mean of its divisors is an integer number (9692550).

Almost surely, 2^128531996 is an apocalyptic number.

It is an amenable number.

128531996 is a deficient number, since it is larger than the sum of its proper divisors (104089204).

128531996 is a wasteful number, since it uses less digits than its factorization.

128531996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9173 (or 9171 counting only the distinct ones).

The product of its digits is 116640, while the sum is 44.

The square root of 128531996 is about 11337.1952439746. The cubic root of 128531996 is about 504.6656558921.

The spelling of 128531996 in words is "one hundred twenty-eight million, five hundred thirty-one thousand, nine hundred ninety-six".