645700800 has 336 divisors, whose sum is σ = 2309664672. Its totient is φ = 157286400.

The previous prime is 645700789. The next prime is 645700813. The reversal of 645700800 is 8007546.

It is a happy number.

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 polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3345504 + ... + 3345696.

It is an arithmetic number, because the mean of its divisors is an integer number (6874002).

Almost surely, 2^645700800 is an apocalyptic number.

645700800 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 645700800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1154832336).

645700800 is an abundant number, since it is smaller than the sum of its proper divisors (1663963872).

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

645700800 is a wasteful number, since it uses less digits than its factorization.

645700800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276 (or 261 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 645700800 is about 25410.6434393150. The cubic root of 645700800 is about 864.3250662982.

The spelling of 645700800 in words is "six hundred forty-five million, seven hundred thousand, eight hundred".