21168922 has 4 divisors (see below), whose sum is σ = 31753386. Its totient is φ = 10584460.

The previous prime is 21168911. The next prime is 21168923. The reversal of 21168922 is 22986112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 15594601 + 5574321 = 3949^2 + 2361^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21168923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5292229 + ... + 5292232.

Almost surely, 2^21168922 is an apocalyptic number.

21168922 is a deficient number, since it is larger than the sum of its proper divisors (10584464).

21168922 is a wasteful number, since it uses less digits than its factorization.

21168922 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10584463.

The product of its digits is 3456, while the sum is 31.

The square root of 21168922 is about 4600.9696804043. The cubic root of 21168922 is about 276.6301937372.

The spelling of 21168922 in words is "twenty-one million, one hundred sixty-eight thousand, nine hundred twenty-two".