1001721288641 has 2 divisors, whose sum is σ = 1001721288642. Its totient is φ = 1001721288640.

The previous prime is 1001721288637. The next prime is 1001721288647. The reversal of 1001721288641 is 1468821271001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 969634090000 + 32087198641 = 984700^2 + 179129^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001721288641 - 2² = 1001721288637 is a prime.

It is not a weakly prime, because it can be changed into another prime (1001721288647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500860644320 + 500860644321.

It is an arithmetic number, because the mean of its divisors is an integer number (500860644321).

Almost surely, 2^{1001721288641} is an apocalyptic number.

It is an amenable number.

1001721288641 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001721288641 is an equidigital number, since it uses as much as digits as its factorization.

1001721288641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43008, while the sum is 41.

The spelling of 1001721288641 in words is "one trillion, one billion, seven hundred twenty-one million, two hundred eighty-eight thousand, six hundred forty-one".