128251656 has 96 divisors (see below), whose sum is σ = 379393560. Its totient is φ = 38900736.

The previous prime is 128251589. The next prime is 128251661. The reversal of 128251656 is 656152821.

128251656 is a `hidden beast` number, since 12 + 82 + 516 + 56 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 99800100 + 28451556 = 9990^2 + 5334^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 128251656.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 67390 + ... + 69266.

Almost surely, 2^128251656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128251656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (189696780).

128251656 is an abundant number, since it is smaller than the sum of its proper divisors (251141904).

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

128251656 is a wasteful number, since it uses less digits than its factorization.

128251656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1975 (or 1968 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The square root of 128251656 is about 11324.8247668562. The cubic root of 128251656 is about 504.2984815490.

The spelling of 128251656 in words is "one hundred twenty-eight million, two hundred fifty-one thousand, six hundred fifty-six".