645992828928 has 312 divisors, whose sum is σ = 1957787919360. Its totient is φ = 204838993920.

The previous prime is 645992828917. The next prime is 645992828947. The reversal of 645992828928 is 829828299546.

645992828928 is a `hidden beast` number, since 6 + 4 + 599 + 2 + 8 + 2 + 8 + 9 + 28 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

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, 161941558 + ... + 161945546.

It is an arithmetic number, because the mean of its divisors is an integer number (6274961280).

Almost surely, 2^645992828928 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 645992828928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (978893959680).

645992828928 is an abundant number, since it is smaller than the sum of its proper divisors (1311795090432).

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

645992828928 is a wasteful number, since it uses less digits than its factorization.

645992828928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4233 (or 4208 counting only the distinct ones).

The product of its digits is 358318080, while the sum is 72.

The spelling of 645992828928 in words is "six hundred forty-five billion, nine hundred ninety-two million, eight hundred twenty-eight thousand, nine hundred twenty-eight".