3681220811693 has 2 divisors, whose sum is σ = 3681220811694. Its totient is φ = 3681220811692.

The previous prime is 3681220811689. The next prime is 3681220811783. The reversal of 3681220811693 is 3961180221863.

It is a happy number.

3681220811693 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3147938223049 + 533282588644 = 1774243^2 + 730262^2 .

It is an emirp because it is prime and its reverse (3961180221863) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3681220811693 - 2² = 3681220811689 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3681220811393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1840610405846 + 1840610405847.

It is an arithmetic number, because the mean of its divisors is an integer number (1840610405847).

Almost surely, 2^{3681220811693} is an apocalyptic number.

It is an amenable number.

3681220811693 is a deficient number, since it is larger than the sum of its proper divisors (1).

3681220811693 is an equidigital number, since it uses as much as digits as its factorization.

3681220811693 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 746496, while the sum is 50.

The spelling of 3681220811693 in words is "three trillion, six hundred eighty-one billion, two hundred twenty million, eight hundred eleven thousand, six hundred ninety-three".