1009 has 2 divisors, whose sum is σ = 1010. Its totient is φ = 1008.

The previous prime is 997. The next prime is 1013. The reversal of 1009 is 9001.

Subtracting from 1009 its sum of digits (10), we obtain a palindrome (999).

It can be divided in two parts, 100 and 9, that multiplied together give a square (900 = 30^{2}).

It is a happy number.

1009 is nontrivially palindromic in base 11 and base 15.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 784 + 225 = 28^2 + 15^2 .

It is an emirp because it is prime and its reverse (9001) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1009 - 2^{5} = 977 is a prime.

It is a Chen prime.

1009 is an undulating number in base 11 and base 15.

1009 is a modest number, since divided by 9 gives 1 as remainder.

1009 is a lucky number.

It is a nialpdrome in base 14.

It is a junction number, because it is equal to *n*+sod(*n*) for *n* = 986 and 1004.

It is not a weakly prime, because it can be changed into another prime (1019) by changing a digit.

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

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 504 + 505.

It is an arithmetic number, because the mean of its divisors is an integer number (505).

It is an amenable number.

1009 is a deficient number, since it is larger than the sum of its proper divisors (1).

1009 is an equidigital number, since it uses as much as digits as its factorization.

1009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9, while the sum is 10.

The square root of 1009 is about 31.7647603485. The cubic root of 1009 is about 10.0299104473.

The spelling of 1009 in words is "one thousand, nine".

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