21212022011 has 4 divisors (see below), whose sum is σ = 21213030432. Its totient is φ = 21211013592.

The previous prime is 21212021959. The next prime is 21212022019. The reversal of 21212022011 is 11022021212.

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 21212022011 - 2⁶ = 21212021947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21212022019) 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 3 ways as a sum of consecutive naturals, for example, 471971 + ... + 514956.

It is an arithmetic number, because the mean of its divisors is an integer number (5303257608).

Almost surely, 2^21212022011 is an apocalyptic number.

21212022011 is a deficient number, since it is larger than the sum of its proper divisors (1008421).

21212022011 is an equidigital number, since it uses as much as digits as its factorization.

21212022011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1008420.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21212022011 its reverse (11022021212), we get a palindrome (32234043223).

The spelling of 21212022011 in words is "twenty-one billion, two hundred twelve million, twenty-two thousand, eleven".