645210715280 has 80 divisors (see below), whose sum is σ = 1590357448704. Its totient is φ = 243008709120.

The previous prime is 645210715229. The next prime is 645210715309. The reversal of 645210715280 is 82517012546.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×645210715280² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3423992 + ... + 3607511.

Almost surely, 2^645210715280 is an apocalyptic number.

It is an amenable number.

645210715280 is an abundant number, since it is smaller than the sum of its proper divisors (945146733424).

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

645210715280 is a wasteful number, since it uses less digits than its factorization.

645210715280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7031584 (or 7031578 counting only the distinct ones).

The product of its (nonzero) digits is 134400, while the sum is 41.

The spelling of 645210715280 in words is "six hundred forty-five billion, two hundred ten million, seven hundred fifteen thousand, two hundred eighty".