21086793 has 24 divisors (see below), whose sum is σ = 37489088. Its totient is φ = 11122272.

The previous prime is 21086753. The next prime is 21086839. The reversal of 21086793 is 39768012.

It is not a de Polignac number, because 21086793 - 2⁹ = 21086281 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21086743) 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, 12055 + ... + 13692.

Almost surely, 2^21086793 is an apocalyptic number.

It is an amenable number.

21086793 is a deficient number, since it is larger than the sum of its proper divisors (16402295).

21086793 is a wasteful number, since it uses less digits than its factorization.

21086793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25773 (or 25770 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 21086793 is about 4592.0358230310. The cubic root of 21086793 is about 276.2719829902.

The spelling of 21086793 in words is "twenty-one million, eighty-six thousand, seven hundred ninety-three".