21212130223 has 4 divisors (see below), whose sum is σ = 21223530328. Its totient is φ = 21200730120.

The previous prime is 21212130211. The next prime is 21212130281. The reversal of 21212130223 is 32203121212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21212130223 - 2²¹ = 21210033071 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21212130223.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212130283) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5697261 + ... + 5700982.

It is an arithmetic number, because the mean of its divisors is an integer number (5305882582).

Almost surely, 2^21212130223 is an apocalyptic number.

21212130223 is a deficient number, since it is larger than the sum of its proper divisors (11400105).

21212130223 is a wasteful number, since it uses less digits than its factorization.

21212130223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11400104.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21212130223 its reverse (32203121212), we get a palindrome (53415251435).

The spelling of 21212130223 in words is "twenty-one billion, two hundred twelve million, one hundred thirty thousand, two hundred twenty-three".