128731816 has 16 divisors (see below), whose sum is σ = 241580340. Its totient is φ = 64310400.

The previous prime is 128731789. The next prime is 128731831. The reversal of 128731816 is 618137821.

It can be written as a sum of positive squares in 2 ways, for example, as 128731716 + 100 = 11346^2 + 10^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3916 + ... + 16516.

Almost surely, 2^128731816 is an apocalyptic number.

It is an amenable number.

128731816 is a deficient number, since it is larger than the sum of its proper divisors (112848524).

128731816 is a wasteful number, since it uses less digits than its factorization.

128731816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13884 (or 13880 counting only the distinct ones).

The product of its digits is 16128, while the sum is 37.

The square root of 128731816 is about 11346.0044068386. The cubic root of 128731816 is about 504.9270436710.

The spelling of 128731816 in words is "one hundred twenty-eight million, seven hundred thirty-one thousand, eight hundred sixteen".