645634624638573 has 12 divisors (see below), whose sum is σ = 933736107337020. Its totient is φ = 429891039721536.

The previous prime is 645634624638551. The next prime is 645634624638587. The reversal of 645634624638573 is 375836426436546.

It is a happy number.

645634624638573 is a `hidden beast` number, since 6 + 4 + 5 + 6 + 3 + 4 + 6 + 2 + 46 + 3 + 8 + 573 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 327633964838244 + 318000659800329 = 18100662^2 + 17832573^2 .

It is not a de Polignac number, because 645634624638573 - 2²⁹ = 645634087767661 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645634624638593) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 44336939886 + ... + 44336954447.

It is an arithmetic number, because the mean of its divisors is an integer number (77811342278085).

Almost surely, 2^{645634624638573} is an apocalyptic number.

It is an amenable number.

645634624638573 is a deficient number, since it is larger than the sum of its proper divisors (288101482698447).

645634624638573 is a wasteful number, since it uses less digits than its factorization.

645634624638573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88673895148 (or 88673895145 counting only the distinct ones).

The product of its digits is 6270566400, while the sum is 72.

The spelling of 645634624638573 in words is "six hundred forty-five trillion, six hundred thirty-four billion, six hundred twenty-four million, six hundred thirty-eight thousand, five hundred seventy-three".