645828756 has 24 divisors (see below), whose sum is σ = 1507524480. Its totient is φ = 215191872.

The previous prime is 645828731. The next prime is 645828779. The reversal of 645828756 is 657828546.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 645828699 and 645828708.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26565 + ... + 44691.

It is an arithmetic number, because the mean of its divisors is an integer number (62813520).

Almost surely, 2^645828756 is an apocalyptic number.

It is an amenable number.

645828756 is an abundant number, since it is smaller than the sum of its proper divisors (861695724).

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

645828756 is a wasteful number, since it uses less digits than its factorization.

645828756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21103 (or 21101 counting only the distinct ones).

The product of its digits is 3225600, while the sum is 51.

The square root of 645828756 is about 25413.1610784648. The cubic root of 645828756 is about 864.3821558323.

The spelling of 645828756 in words is "six hundred forty-five million, eight hundred twenty-eight thousand, seven hundred fifty-six".