643161336653 has 16 divisors (see below), whose sum is σ = 704499690240. Its totient is φ = 582302788800.

The previous prime is 643161336593. The next prime is 643161336659. The reversal of 643161336653 is 356633161346.

It is a cyclic number.

It is not a de Polignac number, because 643161336653 - 2⁸ = 643161336397 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 643161336598 and 643161336607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643161336659) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8237468 + ... + 8315178.

It is an arithmetic number, because the mean of its divisors is an integer number (44031230640).

Almost surely, 2^643161336653 is an apocalyptic number.

It is an amenable number.

643161336653 is a deficient number, since it is larger than the sum of its proper divisors (61338353587).

643161336653 is a wasteful number, since it uses less digits than its factorization.

643161336653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80788.

The product of its digits is 2099520, while the sum is 47.

Adding to 643161336653 its reverse (356633161346), we get a palindrome (999794497999).

The spelling of 643161336653 in words is "six hundred forty-three billion, one hundred sixty-one million, three hundred thirty-six thousand, six hundred fifty-three".