2166706651091 has 2 divisors, whose sum is σ = 2166706651092. Its totient is φ = 2166706651090.

The previous prime is 2166706651073. The next prime is 2166706651093. The reversal of 2166706651091 is 1901566076612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2166706651091 is a prime.

It is a super-2 number, since 2×2166706651091² (a number of 25 digits) contains 22 as substring.

Together with 2166706651093, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2166706651093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1083353325545 + 1083353325546.

It is an arithmetic number, because the mean of its divisors is an integer number (1083353325546).

Almost surely, 2^{2166706651091} is an apocalyptic number.

2166706651091 is a deficient number, since it is larger than the sum of its proper divisors (1).

2166706651091 is an equidigital number, since it uses as much as digits as its factorization.

2166706651091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 816480, while the sum is 50.

The spelling of 2166706651091 in words is "two trillion, one hundred sixty-six billion, seven hundred six million, six hundred fifty-one thousand, ninety-one".