128957728 has 24 divisors (see below), whose sum is σ = 260749692. Its totient is φ = 62735616.

The previous prime is 128957687. The next prime is 128957749. The reversal of 128957728 is 827759821.

It can be written as a sum of positive squares in 2 ways, for example, as 94711824 + 34245904 = 9732^2 + 5852^2 .

It is a super-2 number, since 2×128957728² = 33260191221843968, which contains 22 as substring.

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, 53275 + ... + 55642.

Almost surely, 2^128957728 is an apocalyptic number.

It is an amenable number.

128957728 is an abundant number, since it is smaller than the sum of its proper divisors (131791964).

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

128957728 is a wasteful number, since it uses less digits than its factorization.

128957728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108964 (or 108956 counting only the distinct ones).

The product of its digits is 564480, while the sum is 49.

The square root of 128957728 is about 11355.9556180887. The cubic root of 128957728 is about 505.2222372501. Note that the first 4 decimals are identical.

It can be divided in two parts, 128 and 957728, that multiplied together give a square (122589184 = 11072²).

The spelling of 128957728 in words is "one hundred twenty-eight million, nine hundred fifty-seven thousand, seven hundred twenty-eight".