645025518 has 48 divisors (see below), whose sum is σ = 1469251056. Its totient is φ = 212051520.

The previous prime is 645025517. The next prime is 645025531. The reversal of 645025518 is 815520546.

645025518 is a `hidden beast` number, since 645 + 0 + 2 + 5 + 5 + 1 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645025517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26388 + ... + 44568.

It is an arithmetic number, because the mean of its divisors is an integer number (30609397).

Almost surely, 2^645025518 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645025518, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (734625528).

645025518 is an abundant number, since it is smaller than the sum of its proper divisors (824225538).

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

645025518 is a wasteful number, since it uses less digits than its factorization.

645025518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18271 (or 18259 counting only the distinct ones).

The product of its (nonzero) digits is 48000, while the sum is 36.

The square root of 645025518 is about 25397.3525785661. The cubic root of 645025518 is about 864.0236538663.

The spelling of 645025518 in words is "six hundred forty-five million, twenty-five thousand, five hundred eighteen".