645128848 has 80 divisors (see below), whose sum is σ = 1588120576. Its totient is φ = 246965760.

The previous prime is 645128843. The next prime is 645128947. The reversal of 645128848 is 848821546.

It is a junction number, because it is equal to n+sod(n) for n = 645128798 and 645128807.

It is not an unprimeable number, because it can be changed into a prime (645128843) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37990 + ... + 52282.

Almost surely, 2^645128848 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 645128848, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (794060288).

645128848 is an abundant number, since it is smaller than the sum of its proper divisors (942991728).

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

645128848 is a wasteful number, since it uses less digits than its factorization.

645128848 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14352 (or 14346 counting only the distinct ones).

The product of its digits is 491520, while the sum is 46.

The square root of 645128848 is about 25399.3867642508. The cubic root of 645128848 is about 864.0697888872.

The spelling of 645128848 in words is "six hundred forty-five million, one hundred twenty-eight thousand, eight hundred forty-eight".