643731560051 has 4 divisors (see below), whose sum is σ = 643748758704. Its totient is φ = 643714361400.

The previous prime is 643731560047. The next prime is 643731560057. The reversal of 643731560051 is 150065137346.

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

It is a cyclic number.

It is not a de Polignac number, because 643731560051 - 2² = 643731560047 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 643731559990 and 643731560008.

It is not an unprimeable number, because it can be changed into a prime (643731560057) 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, 8543060 + ... + 8618081.

It is an arithmetic number, because the mean of its divisors is an integer number (160937189676).

Almost surely, 2^643731560051 is an apocalyptic number.

643731560051 is a deficient number, since it is larger than the sum of its proper divisors (17198653).

643731560051 is a wasteful number, since it uses less digits than its factorization.

643731560051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17198652.

The product of its (nonzero) digits is 226800, while the sum is 41.

Adding to 643731560051 its reverse (150065137346), we get a palindrome (793796697397).

The spelling of 643731560051 in words is "six hundred forty-three billion, seven hundred thirty-one million, five hundred sixty thousand, fifty-one".