21009836793 has 16 divisors (see below), whose sum is σ = 30675972096. Its totient is φ = 12684813840.

The previous prime is 21009836791. The next prime is 21009836803. The reversal of 21009836793 is 39763890012.

It is not a de Polignac number, because 21009836793 - 2¹ = 21009836791 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21009836791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1201705 + ... + 1219062.

It is an arithmetic number, because the mean of its divisors is an integer number (1917248256).

Almost surely, 2^21009836793 is an apocalyptic number.

It is an amenable number.

21009836793 is a deficient number, since it is larger than the sum of its proper divisors (9666135303).

21009836793 is a wasteful number, since it uses less digits than its factorization.

21009836793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2421044.

The product of its (nonzero) digits is 489888, while the sum is 48.

The spelling of 21009836793 in words is "twenty-one billion, nine million, eight hundred thirty-six thousand, seven hundred ninety-three".