21212011233 has 24 divisors (see below), whose sum is σ = 35071178688. Its totient is φ = 12102275232.

The previous prime is 21212011187. The next prime is 21212011243. The reversal of 21212011233 is 33211021212.

It is not a de Polignac number, because 21212011233 - 2⁸ = 21212010977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21212011243) 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 in 23 ways as a sum of consecutive naturals, for example, 221310 + ... + 302327.

It is an arithmetic number, because the mean of its divisors is an integer number (1461299112).

Almost surely, 2^21212011233 is an apocalyptic number.

It is an amenable number.

21212011233 is a deficient number, since it is larger than the sum of its proper divisors (13859167455).

21212011233 is a wasteful number, since it uses less digits than its factorization.

21212011233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524293 (or 524290 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21212011233 its reverse (33211021212), we get a palindrome (54423032445).

The spelling of 21212011233 in words is "twenty-one billion, two hundred twelve million, eleven thousand, two hundred thirty-three".