2191549 has 2 divisors, whose sum is σ = 2191550. Its totient is φ = 2191548.

The previous prime is 2191537. The next prime is 2191561. The reversal of 2191549 is 9451912.

2191549 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (2191537) and next prime (2191561).

It can be written as a sum of positive squares in only one way, i.e., 1368900 + 822649 = 1170^2 + 907^2 .

It is a cyclic number.

It is not a de Polignac number, because 2191549 - 2¹⁵ = 2158781 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2191549.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2191529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1095774 + 1095775.

It is an arithmetic number, because the mean of its divisors is an integer number (1095775).

2^2191549 is an apocalyptic number.

It is an amenable number.

2191549 is a deficient number, since it is larger than the sum of its proper divisors (1).

2191549 is an equidigital number, since it uses as much as digits as its factorization.

2191549 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3240, while the sum is 31.

The square root of 2191549 is about 1480.3881247835. The cubic root of 2191549 is about 129.8923961656.

The spelling of 2191549 in words is "two million, one hundred ninety-one thousand, five hundred forty-nine".