645653508 has 12 divisors (see below), whose sum is σ = 1506524880. Its totient is φ = 215217832.

The previous prime is 645653507. The next prime is 645653549. The reversal of 645653508 is 805356546.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 645653508.

It is not an unprimeable number, because it can be changed into a prime (645653507) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26902218 + ... + 26902241.

It is an arithmetic number, because the mean of its divisors is an integer number (125543740).

Almost surely, 2^645653508 is an apocalyptic number.

It is an amenable number.

645653508 is an abundant number, since it is smaller than the sum of its proper divisors (860871372).

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

645653508 is a wasteful number, since it uses less digits than its factorization.

645653508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53804466 (or 53804464 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 42.

The square root of 645653508 is about 25409.7128673269. The cubic root of 645653508 is about 864.3039643373.

The spelling of 645653508 in words is "six hundred forty-five million, six hundred fifty-three thousand, five hundred eight".