645959210775 has 24 divisors (see below), whose sum is σ = 1068093293904. Its totient is φ = 344476934400.

The previous prime is 645959210749. The next prime is 645959210777. The reversal of 645959210775 is 577012959546.

It is a happy number.

It is not a de Polignac number, because 645959210775 - 2¹² = 645959206679 is a prime.

It is a super-2 number, since 2×645959210775² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645959210777) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 326547 + ... + 1182603.

It is an arithmetic number, because the mean of its divisors is an integer number (44503887246).

Almost surely, 2^645959210775 is an apocalyptic number.

645959210775 is a deficient number, since it is larger than the sum of its proper divisors (422134083129).

645959210775 is a wasteful number, since it uses less digits than its factorization.

645959210775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 866131 (or 866126 counting only the distinct ones).

The product of its (nonzero) digits is 23814000, while the sum is 60.

The spelling of 645959210775 in words is "six hundred forty-five billion, nine hundred fifty-nine million, two hundred ten thousand, seven hundred seventy-five".