21804693 has 16 divisors (see below), whose sum is σ = 30934080. Its totient is φ = 13614336.

The previous prime is 21804683. The next prime is 21804701. The reversal of 21804693 is 39640812.

It is not a de Polignac number, because 21804693 - 2¹⁰ = 21803669 is a prime.

It is a super-3 number, since 3×21804693³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21804623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10746 + ... + 12612.

It is an arithmetic number, because the mean of its divisors is an integer number (1933380).

Almost surely, 2^21804693 is an apocalyptic number.

It is an amenable number.

21804693 is a deficient number, since it is larger than the sum of its proper divisors (9129387).

21804693 is a wasteful number, since it uses less digits than its factorization.

21804693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2116.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 21804693 is about 4669.5495500102. The cubic root of 21804693 is about 279.3722885593.

The spelling of 21804693 in words is "twenty-one million, eight hundred four thousand, six hundred ninety-three".