645605260 has 48 divisors (see below), whose sum is σ = 1441661760. Its totient is φ = 242012160.

The previous prime is 645605251. The next prime is 645605263. The reversal of 645605260 is 62506546.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is not an unprimeable number, because it can be changed into a prime (645605263) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78001 + ... + 85879.

It is an arithmetic number, because the mean of its divisors is an integer number (30034620).

Almost surely, 2^645605260 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 645605260, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (720830880).

645605260 is an abundant number, since it is smaller than the sum of its proper divisors (796056500).

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

645605260 is a wasteful number, since it uses less digits than its factorization.

645605260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8146 (or 8144 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 34.

The square root of 645605260 is about 25408.7634488576. The cubic root of 645605260 is about 864.2824347419.

The spelling of 645605260 in words is "six hundred forty-five million, six hundred five thousand, two hundred sixty".