2011221009 has 40 divisors (see below), whose sum is σ = 3439149120. Its totient is φ = 1147418784.

The previous prime is 2011220999. The next prime is 2011221049. The reversal of 2011221009 is 9001221102.

It is not a de Polignac number, because 2011221009 - 2⁷ = 2011220881 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2011220982 and 2011221000.

It is not an unprimeable number, because it can be changed into a prime (2011221049) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 399502 + ... + 404504.

It is an arithmetic number, because the mean of its divisors is an integer number (85978728).

Almost surely, 2^2011221009 is an apocalyptic number.

It is an amenable number.

2011221009 is a deficient number, since it is larger than the sum of its proper divisors (1427928111).

2011221009 is an equidigital number, since it uses as much as digits as its factorization.

2011221009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5731 (or 5722 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 2011221009 is about 44846.6387703694. The cubic root of 2011221009 is about 1262.2729212085.

The spelling of 2011221009 in words is "two billion, eleven million, two hundred twenty-one thousand, nine".