645988052 has 12 divisors (see below), whose sum is σ = 1134116256. Its totient is φ = 321954840.

The previous prime is 645988043. The next prime is 645988067. The reversal of 645988052 is 250889546.

645988052 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 645987988 and 645988006.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 258398 + ... + 260885.

It is an arithmetic number, because the mean of its divisors is an integer number (94509688).

Almost surely, 2^645988052 is an apocalyptic number.

It is an amenable number.

645988052 is a deficient number, since it is larger than the sum of its proper divisors (488128204).

645988052 is a wasteful number, since it uses less digits than its factorization.

645988052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519598 (or 519596 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 47.

The square root of 645988052 is about 25416.2950093046. The cubic root of 645988052 is about 864.4532176524.

The spelling of 645988052 in words is "six hundred forty-five million, nine hundred eighty-eight thousand, fifty-two".