2091706657 has 2 divisors, whose sum is σ = 2091706658. Its totient is φ = 2091706656.

The previous prime is 2091706651. The next prime is 2091706691. The reversal of 2091706657 is 7566071902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2015650816 + 76055841 = 44896^2 + 8721^2 .

It is a cyclic number.

It is not a de Polignac number, because 2091706657 - 2²³ = 2083318049 is a prime.

It is not a weakly prime, because it can be changed into another prime (2091706651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1045853328 + 1045853329.

It is an arithmetic number, because the mean of its divisors is an integer number (1045853329).

Almost surely, 2^2091706657 is an apocalyptic number.

It is an amenable number.

2091706657 is a deficient number, since it is larger than the sum of its proper divisors (1).

2091706657 is an equidigital number, since it uses as much as digits as its factorization.

2091706657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 158760, while the sum is 43.

The square root of 2091706657 is about 45735.1796432462. The cubic root of 2091706657 is about 1278.8911818785.

The spelling of 2091706657 in words is "two billion, ninety-one million, seven hundred six thousand, six hundred fifty-seven".