21031332009 has 16 divisors (see below), whose sum is σ = 31253993280. Its totient is φ = 12501596160.

The previous prime is 21031332001. The next prime is 21031332011. The reversal of 21031332009 is 90023313012.

It is not a de Polignac number, because 21031332009 - 2³ = 21031332001 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21031332009.

It is not an unprimeable number, because it can be changed into a prime (21031332001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10851112 + ... + 10853049.

It is an arithmetic number, because the mean of its divisors is an integer number (1953374580).

Almost surely, 2^21031332009 is an apocalyptic number.

It is an amenable number.

21031332009 is a deficient number, since it is larger than the sum of its proper divisors (10222661271).

21031332009 is a wasteful number, since it uses less digits than its factorization.

21031332009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21704200.

The product of its (nonzero) digits is 972, while the sum is 24.

The spelling of 21031332009 in words is "twenty-one billion, thirty-one million, three hundred thirty-two thousand, nine".