645805888 has 224 divisors, whose sum is σ = 1684121600. Its totient is φ = 243855360.

The previous prime is 645805873. The next prime is 645805903. The reversal of 645805888 is 888508546.

645805888 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (645805873) and next prime (645805903).

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (52).

It is a zygodrome in base 7.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8846620 + ... + 8846692.

It is an arithmetic number, because the mean of its divisors is an integer number (7518400).

Almost surely, 2^645805888 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 645805888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (842060800).

645805888 is an abundant number, since it is smaller than the sum of its proper divisors (1038315712).

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

645805888 is a wasteful number, since it uses less digits than its factorization.

645805888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150 (or 126 counting only the distinct ones).

The product of its (nonzero) digits is 2457600, while the sum is 52.

The square root of 645805888 is about 25412.7111501311. The cubic root of 645805888 is about 864.3719534764.

The spelling of 645805888 in words is "six hundred forty-five million, eight hundred five thousand, eight hundred eighty-eight".