21142223 has 2 divisors, whose sum is σ = 21142224. Its totient is φ = 21142222.

The previous prime is 21142213. The next prime is 21142243. The reversal of 21142223 is 32224112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21142223 - 2²⁴ = 4365007 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21142213) 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, 10571111 + 10571112.

It is an arithmetic number, because the mean of its divisors is an integer number (10571112).

Almost surely, 2^21142223 is an apocalyptic number.

21142223 is a deficient number, since it is larger than the sum of its proper divisors (1).

21142223 is an equidigital number, since it uses as much as digits as its factorization.

21142223 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 192, while the sum is 17.

The square root of 21142223 is about 4598.0673113820. The cubic root of 21142223 is about 276.5138461849.

Adding to 21142223 its reverse (32224112), we get a palindrome (53366335).

The spelling of 21142223 in words is "twenty-one million, one hundred forty-two thousand, two hundred twenty-three".