11211220220021 has 2 divisors, whose sum is σ = 11211220220022. Its totient is φ = 11211220220020.

The previous prime is 11211220220017. The next prime is 11211220220029. The reversal of 11211220220021 is 12002202211211.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7372908396100 + 3838311823921 = 2715310^2 + 1959161^2 .

It is an emirp because it is prime and its reverse (12002202211211) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11211220220021 - 2² = 11211220220017 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11211220220029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5605610110010 + 5605610110011.

It is an arithmetic number, because the mean of its divisors is an integer number (5605610110011).

Almost surely, 2^{11211220220021} is an apocalyptic number.

It is an amenable number.

11211220220021 is a deficient number, since it is larger than the sum of its proper divisors (1).

11211220220021 is an equidigital number, since it uses as much as digits as its factorization.

11211220220021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 11211220220021 its reverse (12002202211211), we get a palindrome (23213422431232).

The spelling of 11211220220021 in words is "eleven trillion, two hundred eleven billion, two hundred twenty million, two hundred twenty thousand, twenty-one".