645890598 has 96 divisors (see below), whose sum is σ = 1543651200. Its totient is φ = 201833856.

The previous prime is 645890587. The next prime is 645890599. The reversal of 645890598 is 895098546.

It is a happy number.

645890598 is a `hidden beast` number, since 6 + 4 + 589 + 0 + 59 + 8 = 666.

645890598 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645890599) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1043133 + ... + 1043751.

It is an arithmetic number, because the mean of its divisors is an integer number (16079700).

Almost surely, 2^645890598 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645890598, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (771825600).

645890598 is an abundant number, since it is smaller than the sum of its proper divisors (897760602).

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

645890598 is a wasteful number, since it uses less digits than its factorization.

645890598 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 768 (or 756 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 54.

The square root of 645890598 is about 25414.3777810908. The cubic root of 645890598 is about 864.4097448873.

The spelling of 645890598 in words is "six hundred forty-five million, eight hundred ninety thousand, five hundred ninety-eight".