646634143013 has 4 divisors (see below), whose sum is σ = 650752831980. Its totient is φ = 642515454048.

The previous prime is 646634142997. The next prime is 646634143033. The reversal of 646634143013 is 310341436646.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 310341436646 = 2 ⋅155170718323.

It can be written as a sum of positive squares in 2 ways, for example, as 326587104484 + 320047038529 = 571478^2 + 565727^2 .

It is a cyclic number.

It is not a de Polignac number, because 646634143013 - 2⁴ = 646634142997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646634143033) 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, 2059344248 + ... + 2059344561.

It is an arithmetic number, because the mean of its divisors is an integer number (162688207995).

Almost surely, 2^646634143013 is an apocalyptic number.

It is an amenable number.

646634143013 is a deficient number, since it is larger than the sum of its proper divisors (4118688967).

646634143013 is a wasteful number, since it uses less digits than its factorization.

646634143013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4118688966.

The product of its (nonzero) digits is 373248, while the sum is 41.

Adding to 646634143013 its reverse (310341436646), we get a palindrome (956975579659).

The spelling of 646634143013 in words is "six hundred forty-six billion, six hundred thirty-four million, one hundred forty-three thousand, thirteen".