645120404252 has 48 divisors (see below), whose sum is σ = 1160996004000. Its totient is φ = 313535861760.

The previous prime is 645120404213. The next prime is 645120404281. The reversal of 645120404252 is 252404021546.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 45574808 + ... + 45588960.

It is an arithmetic number, because the mean of its divisors is an integer number (24187416750).

Almost surely, 2^645120404252 is an apocalyptic number.

It is an amenable number.

645120404252 is a deficient number, since it is larger than the sum of its proper divisors (515875599748).

645120404252 is a wasteful number, since it uses less digits than its factorization.

645120404252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16406 (or 16404 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 35.

Adding to 645120404252 its reverse (252404021546), we get a palindrome (897524425798).

The spelling of 645120404252 in words is "six hundred forty-five billion, one hundred twenty million, four hundred four thousand, two hundred fifty-two".