21212122011 has 16 divisors (see below), whose sum is σ = 30019773600. Its totient is φ = 13277011968.

The previous prime is 21212121971. The next prime is 21212122027. The reversal of 21212122011 is 11022121212.

It is not a de Polignac number, because 21212122011 - 2⁶ = 21212121947 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21212122051) 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 15 ways as a sum of consecutive naturals, for example, 487606 + ... + 529323.

It is an arithmetic number, because the mean of its divisors is an integer number (1876235850).

Almost surely, 2^21212122011 is an apocalyptic number.

21212122011 is a deficient number, since it is larger than the sum of its proper divisors (8807651589).

21212122011 is a wasteful number, since it uses less digits than its factorization.

21212122011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1017358.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21212122011 its reverse (11022121212), we get a palindrome (32234243223).

The spelling of 21212122011 in words is "twenty-one billion, two hundred twelve million, one hundred twenty-two thousand, eleven".