645388000 has 96 divisors (see below), whose sum is σ = 1679172768. Its totient is φ = 242944000.

The previous prime is 645387971. The next prime is 645388031. The reversal of 645388000 is 883546.

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

It is a congruent number.

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, 63255 + ... + 72745.

It is an arithmetic number, because the mean of its divisors is an integer number (17491383).

Almost surely, 2^645388000 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 645388000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (839586384).

645388000 is an abundant number, since it is smaller than the sum of its proper divisors (1033784768).

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

645388000 is a wasteful number, since it uses less digits than its factorization.

645388000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9533 (or 9515 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 645388000 is about 25404.4877925141. The cubic root of 645388000 is about 864.1854740134.

The spelling of 645388000 in words is "six hundred forty-five million, three hundred eighty-eight thousand".