645974800800 has 864 divisors, whose sum is σ = 2593618997760. Its totient is φ = 138997555200.

The previous prime is 645974800787. The next prime is 645974800843. The reversal of 645974800800 is 8008479546.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 134884806 + ... + 134889594.

It is an arithmetic number, because the mean of its divisors is an integer number (3001873840).

Almost surely, 2^645974800800 is an apocalyptic number.

645974800800 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645974800800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1296809498880).

645974800800 is an abundant number, since it is smaller than the sum of its proper divisors (1947644196960).

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

645974800800 is a wasteful number, since it uses less digits than its factorization.

645974800800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4894 (or 4874 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 51.

The spelling of 645974800800 in words is "six hundred forty-five billion, nine hundred seventy-four million, eight hundred thousand, eight hundred".