2100991 has 2 divisors, whose sum is σ = 2100992. Its totient is φ = 2100990.

The previous prime is 2100983. The next prime is 2100997. The reversal of 2100991 is 1990012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2100991 - 2³ = 2100983 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 (2100997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050495 + 1050496.

It is an arithmetic number, because the mean of its divisors is an integer number (1050496).

2^2100991 is an apocalyptic number.

2100991 is a deficient number, since it is larger than the sum of its proper divisors (1).

2100991 is an equidigital number, since it uses as much as digits as its factorization.

2100991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 2100991 is about 1449.4795617738. The cubic root of 2100991 is about 128.0780570445.

The spelling of 2100991 in words is "two million, one hundred thousand, nine hundred ninety-one".