645865852 has 24 divisors (see below), whose sum is σ = 1181470752. Its totient is φ = 308352000.

The previous prime is 645865789. The next prime is 645865859. The reversal of 645865852 is 258568546.

It is a junction number, because it is equal to n+sod(n) for n = 645865796 and 645865805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645865859) 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 7 ways as a sum of consecutive naturals, for example, 49452 + ... + 61132.

It is an arithmetic number, because the mean of its divisors is an integer number (49227948).

Almost surely, 2^645865852 is an apocalyptic number.

It is an amenable number.

645865852 is a deficient number, since it is larger than the sum of its proper divisors (535604900).

645865852 is a wasteful number, since it uses less digits than its factorization.

645865852 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12309 (or 12307 counting only the distinct ones).

The product of its digits is 2304000, while the sum is 49.

The square root of 645865852 is about 25413.8909260270. The cubic root of 645865852 is about 864.3987053723.

The spelling of 645865852 in words is "six hundred forty-five million, eight hundred sixty-five thousand, eight hundred fifty-two".