645212060720 has 80 divisors (see below), whose sum is σ = 1513888729920. Its totient is φ = 255724864512.

The previous prime is 645212060707. The next prime is 645212060741. The reversal of 645212060720 is 27060212546.

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

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4437494 + ... + 4580586.

It is an arithmetic number, because the mean of its divisors is an integer number (18923609124).

Almost surely, 2^645212060720 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 645212060720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (756944364960).

645212060720 is an abundant number, since it is smaller than the sum of its proper divisors (868676669200).

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

645212060720 is a wasteful number, since it uses less digits than its factorization.

645212060720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143622 (or 143616 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 35.

The spelling of 645212060720 in words is "six hundred forty-five billion, two hundred twelve million, sixty thousand, seven hundred twenty".