1091549 has 2 divisors, whose sum is σ = 1091550. Its totient is φ = 1091548.

The previous prime is 1091527. The next prime is 1091551. The reversal of 1091549 is 9451901.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1036324 + 55225 = 1018^2 + 235^2 .

It is a cyclic number.

It is not a de Polignac number, because 1091549 - 2¹² = 1087453 is a prime.

Together with 1091551, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1091509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 545774 + 545775.

It is an arithmetic number, because the mean of its divisors is an integer number (545775).

2^1091549 is an apocalyptic number.

It is an amenable number.

1091549 is a deficient number, since it is larger than the sum of its proper divisors (1).

1091549 is an equidigital number, since it uses as much as digits as its factorization.

1091549 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 1091549 is about 1044.7722239799. The cubic root of 1091549 is about 102.9629740923.

The spelling of 1091549 in words is "one million, ninety-one thousand, five hundred forty-nine".