101009 has 2 divisors, whose sum is σ = 101010. Its totient is φ = 101008.

The previous prime is 100999. The next prime is 101021. The reversal of 101009 is 900101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61009 + 40000 = 247^2 + 200^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-101009 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (101089) 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, 50504 + 50505.

It is an arithmetic number, because the mean of its divisors is an integer number (50505).

2¹⁰¹⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

101009 is a deficient number, since it is larger than the sum of its proper divisors (1).

101009 is an equidigital number, since it uses as much as digits as its factorization.

101009 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 11.

The square root of 101009 is about 317.8191309534. The cubic root of 101009 is about 46.5714783071.

The spelling of 101009 in words is "one hundred one thousand, nine".