645555330 has 96 divisors (see below), whose sum is σ = 1924401024. Its totient is φ = 147080448.

The previous prime is 645555319. The next prime is 645555347. The reversal of 645555330 is 33555546.

645555330 is a `hidden beast` number, since 645 + 5 + 5 + 5 + 3 + 3 + 0 = 666.

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 47 ways as a sum of consecutive naturals, for example, 217134 + ... + 220086.

It is an arithmetic number, because the mean of its divisors is an integer number (20045844).

Almost surely, 2^645555330 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645555330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (962200512).

645555330 is an abundant number, since it is smaller than the sum of its proper divisors (1278845694).

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

645555330 is a wasteful number, since it uses less digits than its factorization.

645555330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3320 (or 3317 counting only the distinct ones).

The product of its (nonzero) digits is 135000, while the sum is 36.

The square root of 645555330 is about 25407.7808948361. The cubic root of 645555330 is about 864.2601534620.

The spelling of 645555330 in words is "six hundred forty-five million, five hundred fifty-five thousand, three hundred thirty".