21211221223 has 2 divisors, whose sum is σ = 21211221224. Its totient is φ = 21211221222.

The previous prime is 21211221179. The next prime is 21211221277. The reversal of 21211221223 is 32212211212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21211221223 - 2⁹ = 21211220711 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21211221223.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21211225223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605610611 + 10605610612.

It is an arithmetic number, because the mean of its divisors is an integer number (10605610612).

Almost surely, 2^21211221223 is an apocalyptic number.

21211221223 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211221223 is an equidigital number, since it uses as much as digits as its factorization.

21211221223 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 192, while the sum is 19.

Adding to 21211221223 its reverse (32212211212), we get a palindrome (53423432435).

The spelling of 21211221223 in words is "twenty-one billion, two hundred eleven million, two hundred twenty-one thousand, two hundred twenty-three".