643126564504331 has 4 divisors (see below), whose sum is σ = 648817950031032. Its totient is φ = 637435178977632.

The previous prime is 643126564504297. The next prime is 643126564504343. The reversal of 643126564504331 is 133405465621346.

It is a happy number.

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 643126564504331 - 2³⁰ = 643125490762507 is a prime.

It is a super-2 number, since 2×643126564504331² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643126564504231) 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, 2845692763181 + ... + 2845692763406.

It is an arithmetic number, because the mean of its divisors is an integer number (162204487507758).

Almost surely, 2^{643126564504331} is an apocalyptic number.

643126564504331 is a deficient number, since it is larger than the sum of its proper divisors (5691385526701).

643126564504331 is a wasteful number, since it uses less digits than its factorization.

643126564504331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5691385526700.

The product of its (nonzero) digits is 18662400, while the sum is 53.

The spelling of 643126564504331 in words is "six hundred forty-three trillion, one hundred twenty-six billion, five hundred sixty-four million, five hundred four thousand, three hundred thirty-one".