645744760 has 48 divisors (see below), whose sum is σ = 1487670840. Its totient is φ = 252262080.

The previous prime is 645744733. The next prime is 645744761. The reversal of 645744760 is 67447546.

645744760 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645744761) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69595 + ... + 78325.

Almost surely, 2^645744760 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 645744760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (743835420).

645744760 is an abundant number, since it is smaller than the sum of its proper divisors (841926080).

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

645744760 is a wasteful number, since it uses less digits than its factorization.

645744760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8828 (or 8781 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 43.

The square root of 645744760 is about 25411.5084164636. The cubic root of 645744760 is about 864.3446805776.

The spelling of 645744760 in words is "six hundred forty-five million, seven hundred forty-four thousand, seven hundred sixty".