21134221 has 2 divisors, whose sum is σ = 21134222. Its totient is φ = 21134220.

The previous prime is 21134173. The next prime is 21134231. The reversal of 21134221 is 12243112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20124196 + 1010025 = 4486^2 + 1005^2 .

It is a cyclic number.

It is not a de Polignac number, because 21134221 - 2⁷ = 21134093 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21134195 and 21134204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21134231) 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 as a sum of consecutive naturals, namely, 10567110 + 10567111.

It is an arithmetic number, because the mean of its divisors is an integer number (10567111).

Almost surely, 2^21134221 is an apocalyptic number.

It is an amenable number.

21134221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21134221 is an equidigital number, since it uses as much as digits as its factorization.

21134221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96, while the sum is 16.

The square root of 21134221 is about 4597.1970808309. The cubic root of 21134221 is about 276.4789563973.

Adding to 21134221 its reverse (12243112), we get a palindrome (33377333).

The spelling of 21134221 in words is "twenty-one million, one hundred thirty-four thousand, two hundred twenty-one".