645217683968 has 320 divisors, whose sum is σ = 1599366384000. Its totient is φ = 255653314560.

The previous prime is 645217683893. The next prime is 645217683983. The reversal of 645217683968 is 869386712546.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 624605180 + ... + 624606212.

It is an arithmetic number, because the mean of its divisors is an integer number (4998019950).

Almost surely, 2^645217683968 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 645217683968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (799683192000).

645217683968 is an abundant number, since it is smaller than the sum of its proper divisors (954148700032).

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

645217683968 is a wasteful number, since it uses less digits than its factorization.

645217683968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1543 (or 1527 counting only the distinct ones).

The product of its digits is 104509440, while the sum is 65.

The spelling of 645217683968 in words is "six hundred forty-five billion, two hundred seventeen million, six hundred eighty-three thousand, nine hundred sixty-eight".