645684480 has 576 divisors, whose sum is σ = 2790305280. Its totient is φ = 138018816.

The previous prime is 645684439. The next prime is 645684491. The reversal of 645684480 is 84486546.

645684480 is a `hidden beast` number, since 6 + 4 + 568 + 4 + 4 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (45).

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 63 ways as a sum of consecutive naturals, for example, 4112562 + ... + 4112718.

It is an arithmetic number, because the mean of its divisors is an integer number (4844280).

Almost surely, 2^645684480 is an apocalyptic number.

645684480 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 645684480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1395152640).

645684480 is an abundant number, since it is smaller than the sum of its proper divisors (2144620800).

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

645684480 is a wasteful number, since it uses less digits than its factorization.

645684480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211 (or 191 counting only the distinct ones).

The product of its (nonzero) digits is 737280, while the sum is 45.

The square root of 645684480 is about 25410.3223120054. The cubic root of 645684480 is about 864.3177843373.

The spelling of 645684480 in words is "six hundred forty-five million, six hundred eighty-four thousand, four hundred eighty".