21221211212011 has 8 divisors (see below), whose sum is σ = 22473816588720. Its totient is φ = 19969083483648.

The previous prime is 21221211211933. The next prime is 21221211212039. The reversal of 21221211212011 is 11021211212212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21221211212011 - 2¹⁷ = 21221211080939 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 21221211212011.

It is not an unprimeable number, because it can be changed into a prime (21221211212611) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119320606 + ... + 119498323.

It is an arithmetic number, because the mean of its divisors is an integer number (2809227073590).

Almost surely, 2^{21221211212011} is an apocalyptic number.

21221211212011 is a deficient number, since it is larger than the sum of its proper divisors (1252605376709).

21221211212011 is a wasteful number, since it uses less digits than its factorization.

21221211212011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238824173.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21221211212011 its reverse (11021211212212), we get a palindrome (32242422424223).

The spelling of 21221211212011 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred eleven million, two hundred twelve thousand, eleven".