21003111009 has 24 divisors (see below), whose sum is σ = 30463804800. Its totient is φ = 13944018240.

The previous prime is 21003110993. The next prime is 21003111011. The reversal of 21003111009 is 90011130012.

It is not a de Polignac number, because 21003111009 - 2⁴ = 21003110993 is a prime.

It is a super-2 number, since 2×21003111009² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21003110982 and 21003111000.

It is not an unprimeable number, because it can be changed into a prime (21003111079) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3689037 + ... + 3694725.

It is an arithmetic number, because the mean of its divisors is an integer number (1269325200).

Almost surely, 2^21003111009 is an apocalyptic number.

It is an amenable number.

21003111009 is a deficient number, since it is larger than the sum of its proper divisors (9460693791).

21003111009 is a wasteful number, since it uses less digits than its factorization.

21003111009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7325 (or 7322 counting only the distinct ones).

The product of its (nonzero) digits is 54, while the sum is 18.

The spelling of 21003111009 in words is "twenty-one billion, three million, one hundred eleven thousand, nine".