128025640 has 32 divisors (see below), whose sum is σ = 305003880. Its totient is φ = 48197632.

The previous prime is 128025631. The next prime is 128025643. The reversal of 128025640 is 46520821.

It can be written as a sum of positive squares in 4 ways, for example, as 128006596 + 19044 = 11314^2 + 138^2 .

It is a junction number, because it is equal to n+sod(n) for n = 128025599 and 128025608.

It is not an unprimeable number, because it can be changed into a prime (128025643) 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, 93457 + ... + 94816.

Almost surely, 2^128025640 is an apocalyptic number.

128025640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128025640 is an abundant number, since it is smaller than the sum of its proper divisors (176978240).

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

128025640 is a wasteful number, since it uses less digits than its factorization.

128025640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188301 (or 188297 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 128025640 is about 11314.8415808618. The cubic root of 128025640 is about 504.0020681027.

The spelling of 128025640 in words is "one hundred twenty-eight million, twenty-five thousand, six hundred forty".