128531872 has 48 divisors (see below), whose sum is σ = 290001600. Its totient is φ = 54931968.

The previous prime is 128531869. The next prime is 128531873. The reversal of 128531872 is 278135821.

It is not an unprimeable number, because it can be changed into a prime (128531873) 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, 122004 + ... + 123052.

It is an arithmetic number, because the mean of its divisors is an integer number (6041700).

Almost surely, 2^128531872 is an apocalyptic number.

It is an amenable number.

128531872 is an abundant number, since it is smaller than the sum of its proper divisors (161469728).

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

128531872 is a wasteful number, since it uses less digits than its factorization.

128531872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1613 (or 1605 counting only the distinct ones).

The product of its digits is 26880, while the sum is 37.

The square root of 128531872 is about 11337.1897752485. The cubic root of 128531872 is about 504.6654936016.

The spelling of 128531872 in words is "one hundred twenty-eight million, five hundred thirty-one thousand, eight hundred seventy-two".