635640056813 has 4 divisors (see below), whose sum is σ = 636670268220. Its totient is φ = 634609845408.

The previous prime is 635640056803. The next prime is 635640056867. The reversal of 635640056813 is 318650046536.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 220386119209 + 415253937604 = 469453^2 + 644402^2 .

It is a cyclic number.

It is not a de Polignac number, because 635640056813 - 2⁴ = 635640056797 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (635640056803) 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, 515104778 + ... + 515106011.

It is an arithmetic number, because the mean of its divisors is an integer number (159167567055).

Almost surely, 2^635640056813 is an apocalyptic number.

It is an amenable number.

635640056813 is a deficient number, since it is larger than the sum of its proper divisors (1030211407).

635640056813 is a wasteful number, since it uses less digits than its factorization.

635640056813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1030211406.

The product of its (nonzero) digits is 1555200, while the sum is 47.

The spelling of 635640056813 in words is "six hundred thirty-five billion, six hundred forty million, fifty-six thousand, eight hundred thirteen".