21112023221 has 2 divisors, whose sum is σ = 21112023222. Its totient is φ = 21112023220.

The previous prime is 21112023193. The next prime is 21112023263. The reversal of 21112023221 is 12232021112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20731968196 + 380055025 = 143986^2 + 19495^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112023221 - 2¹⁴ = 21112006837 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21112023221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21112023271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556011610 + 10556011611.

It is an arithmetic number, because the mean of its divisors is an integer number (10556011611).

Almost surely, 2^21112023221 is an apocalyptic number.

It is an amenable number.

21112023221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112023221 is an equidigital number, since it uses as much as digits as its factorization.

21112023221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21112023221 its reverse (12232021112), we get a palindrome (33344044333).

The spelling of 21112023221 in words is "twenty-one billion, one hundred twelve million, twenty-three thousand, two hundred twenty-one".