645744000 has 256 divisors, whose sum is σ = 2337154560. Its totient is φ = 156416000.

The previous prime is 645743953. The next prime is 645744019. The reversal of 645744000 is 447546.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 527389 + ... + 528611.

It is an arithmetic number, because the mean of its divisors is an integer number (9129510).

Almost surely, 2^645744000 is an apocalyptic number.

645744000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645744000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1168577280).

645744000 is an abundant number, since it is smaller than the sum of its proper divisors (1691410560).

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

645744000 is a wasteful number, since it uses less digits than its factorization.

645744000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1266 (or 1244 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 30.

The square root of 645744000 is about 25411.4934626047. The cubic root of 645744000 is about 864.3443414847.

The spelling of 645744000 in words is "six hundred forty-five million, seven hundred forty-four thousand".