2101391 has 2 divisors, whose sum is σ = 2101392. Its totient is φ = 2101390.

The previous prime is 2101357. The next prime is 2101423. The reversal of 2101391 is 1931012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2101391 - 2⁶ = 2101327 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2101091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050695 + 1050696.

It is an arithmetic number, because the mean of its divisors is an integer number (1050696).

2^2101391 is an apocalyptic number.

2101391 is a deficient number, since it is larger than the sum of its proper divisors (1).

2101391 is an equidigital number, since it uses as much as digits as its factorization.

2101391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54, while the sum is 17.

The square root of 2101391 is about 1449.6175357659. The cubic root of 2101391 is about 128.0861846331.

The spelling of 2101391 in words is "two million, one hundred one thousand, three hundred ninety-one".