21168733 has 4 divisors (see below), whose sum is σ = 21178108. Its totient is φ = 21159360.

The previous prime is 21168713. The next prime is 21168767. The reversal of 21168733 is 33786112.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 5184729 + 15984004 = 2277^2 + 3998^2 .

It is a cyclic number.

It is not a de Polignac number, because 21168733 - 2⁵ = 21168701 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21168695 and 21168704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21168703) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1003 + ... + 6583.

It is an arithmetic number, because the mean of its divisors is an integer number (5294527).

Almost surely, 2^21168733 is an apocalyptic number.

It is an amenable number.

21168733 is a deficient number, since it is larger than the sum of its proper divisors (9375).

21168733 is an equidigital number, since it uses as much as digits as its factorization.

21168733 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9374.

The product of its digits is 6048, while the sum is 31.

The square root of 21168733 is about 4600.9491412099. The cubic root of 21168733 is about 276.6293704664.

The spelling of 21168733 in words is "twenty-one million, one hundred sixty-eight thousand, seven hundred thirty-three".