646868606868646 has 8 divisors (see below), whose sum is σ = 970303955940720. Its totient is φ = 323433954888408.

The previous prime is 646868606868619. The next prime is 646868606868647.

646868606868646 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646868606868647) 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, 171946866 + ... + 175668613.

It is an arithmetic number, because the mean of its divisors is an integer number (121287994492590).

Almost surely, 2^{646868606868646} is an apocalyptic number.

646868606868646 is a deficient number, since it is larger than the sum of its proper divisors (323435349072074).

646868606868646 is a wasteful number, since it uses less digits than its factorization.

646868606868646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348545918.

The product of its (nonzero) digits is 110075314176, while the sum is 88.

The spelling of 646868606868646 in words is "six hundred forty-six trillion, eight hundred sixty-eight billion, six hundred six million, eight hundred sixty-eight thousand, six hundred forty-six".