1549 has 2 divisors, whose sum is σ = 1550.
Its totient is φ = 1548.
The previous prime is 1543. The next prime is 1553. The reversal of 1549 is 9451.
Subtracting from 1549 its product of digits (180), we obtain a square (1369 = 372).
It can be divided in two parts, 15 and 49, that added together give a 6-th power (64 = 26).
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 1225 + 324 = 35^2 + 18^2
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-1549 is a prime.
It is a plaindrome in base 11.
It is a nialpdrome in base 9, base 12 and base 13.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (1543) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (5) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 774 + 775.
It is an arithmetic number, because the mean of its divisors is an integer number (775).
It is an amenable number.
1549 is a deficient number, since it is larger than the sum of its proper divisors (1).
1549 is an equidigital number, since it uses as much as digits as its factorization.
1549 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 180, while the sum is 19.
The square root of 1549 is about 39.3573373083.
The cubic root of 1549 is about 11.5704559318.
The spelling of 1549 in words is "one thousand, five hundred forty-nine".