21211221111211 has 8 divisors (see below), whose sum is σ = 21728914704000. Its totient is φ = 20693544029760.

The previous prime is 21211221111203. The next prime is 21211221111217. The reversal of 21211221111211 is 11211112211212.

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 21211221111211 - 2³ = 21211221111203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21211221111217) 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, 1507131 + ... + 6685348.

It is an arithmetic number, because the mean of its divisors is an integer number (2716114338000).

Almost surely, 2^{21211221111211} is an apocalyptic number.

21211221111211 is a deficient number, since it is larger than the sum of its proper divisors (517693592789).

21211221111211 is an equidigital number, since it uses as much as digits as its factorization.

21211221111211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8255669.

The product of its digits is 32, while the sum is 19.

Adding to 21211221111211 its reverse (11211112211212), we get a palindrome (32422333322423).

The spelling of 21211221111211 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-one million, one hundred eleven thousand, two hundred eleven".