21212412243 has 32 divisors (see below), whose sum is σ = 32207914752. Its totient is φ = 12303446400.

The previous prime is 21212412227. The next prime is 21212412271. The reversal of 21212412243 is 34221421212.

It is not a de Polignac number, because 21212412243 - 2⁴ = 21212412227 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21212412203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 67921 + ... + 216882.

It is an arithmetic number, because the mean of its divisors is an integer number (1006497336).

Almost surely, 2^21212412243 is an apocalyptic number.

21212412243 is a deficient number, since it is larger than the sum of its proper divisors (10995502509).

21212412243 is a wasteful number, since it uses less digits than its factorization.

21212412243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284915.

The product of its digits is 1536, while the sum is 24.

Adding to 21212412243 its reverse (34221421212), we get a palindrome (55433833455).

The spelling of 21212412243 in words is "twenty-one billion, two hundred twelve million, four hundred twelve thousand, two hundred forty-three".