2163773278661 has 2 divisors, whose sum is σ = 2163773278662. Its totient is φ = 2163773278660.

The previous prime is 2163773278657. The next prime is 2163773278669. The reversal of 2163773278661 is 1668723773612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1925658557761 + 238114720900 = 1387681^2 + 487970^2 .

It is a cyclic number.

It is not a de Polignac number, because 2163773278661 - 2² = 2163773278657 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2163773278661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2163773278669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1081886639330 + 1081886639331.

It is an arithmetic number, because the mean of its divisors is an integer number (1081886639331).

Almost surely, 2^{2163773278661} is an apocalyptic number.

It is an amenable number.

2163773278661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2163773278661 is an equidigital number, since it uses as much as digits as its factorization.

2163773278661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21337344, while the sum is 59.

The spelling of 2163773278661 in words is "two trillion, one hundred sixty-three billion, seven hundred seventy-three million, two hundred seventy-eight thousand, six hundred sixty-one".