2166996661 has 2 divisors, whose sum is σ = 2166996662. Its totient is φ = 2166996660.

The previous prime is 2166996583. The next prime is 2166996673. The reversal of 2166996661 is 1666996612.

2166996661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2098189636 + 68807025 = 45806^2 + 8295^2 .

It is a cyclic number.

It is not a de Polignac number, because 2166996661 - 2²¹ = 2164899509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2166996599 and 2166996608.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2166996061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1083498330 + 1083498331.

It is an arithmetic number, because the mean of its divisors is an integer number (1083498331).

Almost surely, 2^2166996661 is an apocalyptic number.

It is an amenable number.

2166996661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2166996661 is an equidigital number, since it uses as much as digits as its factorization.

2166996661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1259712, while the sum is 52.

The square root of 2166996661 is about 46551.0113853609. The cubic root of 2166996661 is about 1294.0550364901.

The spelling of 2166996661 in words is "two billion, one hundred sixty-six million, nine hundred ninety-six thousand, six hundred sixty-one".