2116991 has 2 divisors, whose sum is σ = 2116992. Its totient is φ = 2116990.

The previous prime is 2116987. The next prime is 2116997. The reversal of 2116991 is 1996112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2116991 - 2² = 2116987 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2116997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1058495 + 1058496.

It is an arithmetic number, because the mean of its divisors is an integer number (1058496).

2^2116991 is an apocalyptic number.

2116991 is a deficient number, since it is larger than the sum of its proper divisors (1).

2116991 is an equidigital number, since it uses as much as digits as its factorization.

2116991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 972, while the sum is 29.

The square root of 2116991 is about 1454.9883161043. The cubic root of 2116991 is about 128.4023593734.

The spelling of 2116991 in words is "two million, one hundred sixteen thousand, nine hundred ninety-one".