21202121223 has 20 divisors (see below), whose sum is σ = 33339270360. Its totient is φ = 13390812432.

The previous prime is 21202121221. The next prime is 21202121263. The reversal of 21202121223 is 32212120212.

It is not a de Polignac number, because 21202121223 - 2¹ = 21202121221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21202121196 and 21202121205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202121221) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6886740 + ... + 6889817.

It is an arithmetic number, because the mean of its divisors is an integer number (1666963518).

Almost surely, 2^21202121223 is an apocalyptic number.

21202121223 is a deficient number, since it is larger than the sum of its proper divisors (12137149137).

21202121223 is a wasteful number, since it uses less digits than its factorization.

21202121223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13776588 (or 13776579 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21202121223 its reverse (32212120212), we get a palindrome (53414241435).

The spelling of 21202121223 in words is "twenty-one billion, two hundred two million, one hundred twenty-one thousand, two hundred twenty-three".