645758207128 has 8 divisors (see below), whose sum is σ = 1210796638380. Its totient is φ = 322879103560.

The previous prime is 645758207119. The next prime is 645758207141. The reversal of 645758207128 is 821702857546.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40359887938 + ... + 40359887953.

Almost surely, 2^645758207128 is an apocalyptic number.

It is an amenable number.

645758207128 is a deficient number, since it is larger than the sum of its proper divisors (565038431252).

645758207128 is a wasteful number, since it uses less digits than its factorization.

645758207128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80719775897 (or 80719775893 counting only the distinct ones).

The product of its (nonzero) digits is 7526400, while the sum is 55.

The spelling of 645758207128 in words is "six hundred forty-five billion, seven hundred fifty-eight million, two hundred seven thousand, one hundred twenty-eight".