646680704641 has 4 divisors (see below), whose sum is σ = 646763737300. Its totient is φ = 646597671984.

The previous prime is 646680704611. The next prime is 646680704737. The reversal of 646680704641 is 146407086646.

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 188967567616 + 457713137025 = 434704^2 + 676545^2 .

It is a cyclic number.

It is not a de Polignac number, because 646680704641 - 2²⁹ = 646143833729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646680704611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41504646 + ... + 41520223.

It is an arithmetic number, because the mean of its divisors is an integer number (161690934325).

Almost surely, 2^646680704641 is an apocalyptic number.

It is an amenable number.

646680704641 is a deficient number, since it is larger than the sum of its proper divisors (83032659).

646680704641 is an equidigital number, since it uses as much as digits as its factorization.

646680704641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83032658.

The product of its (nonzero) digits is 4644864, while the sum is 52.

The spelling of 646680704641 in words is "six hundred forty-six billion, six hundred eighty million, seven hundred four thousand, six hundred forty-one".