643461014321 has 4 divisors (see below), whose sum is σ = 659155185444. Its totient is φ = 627766843200.

The previous prime is 643461014309. The next prime is 643461014341. The reversal of 643461014321 is 123410164346.

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 149162026225 + 494298988096 = 386215^2 + 703064^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643461014321 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (643461014341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7847085500 + ... + 7847085581.

It is an arithmetic number, because the mean of its divisors is an integer number (164788796361).

Almost surely, 2^643461014321 is an apocalyptic number.

It is an amenable number.

643461014321 is a deficient number, since it is larger than the sum of its proper divisors (15694171123).

643461014321 is a wasteful number, since it uses less digits than its factorization.

643461014321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15694171122.

The product of its (nonzero) digits is 41472, while the sum is 35.

Adding to 643461014321 its reverse (123410164346), we get a palindrome (766871178667).

The spelling of 643461014321 in words is "six hundred forty-three billion, four hundred sixty-one million, fourteen thousand, three hundred twenty-one".