641767618816 has 27 divisors (see below), whose sum is σ = 1281053918641. Its totient is φ = 320877400576.

The previous prime is 641767618787. The next prime is 641767618901. The reversal of 641767618816 is 618816767146.

The square root of 641767618816 is 801104.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 459814185216 + 181953433600 = 678096^2 + 426560^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 12792630 + ... + 12842698.

Almost surely, 2^641767618816 is an apocalyptic number.

641767618816 is the 801104-th square number.

It is an amenable number.

641767618816 is a deficient number, since it is larger than the sum of its proper divisors (639286299825).

641767618816 is an frugal number, since it uses more digits than its factorization.

641767618816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100154 (or 50071 counting only the distinct ones).

The product of its digits is 16257024, while the sum is 61.

The spelling of 641767618816 in words is "six hundred forty-one billion, seven hundred sixty-seven million, six hundred eighteen thousand, eight hundred sixteen".