220211111921 has 2 divisors, whose sum is σ = 220211111922. Its totient is φ = 220211111920.

The previous prime is 220211111851. The next prime is 220211112041. The reversal of 220211111921 is 129111112022.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166026911296 + 54184200625 = 407464^2 + 232775^2 .

It is a cyclic number.

It is not a de Polignac number, because 220211111921 - 2³⁰ = 219137370097 is a prime.

It is not a weakly prime, because it can be changed into another prime (220211111321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110105555960 + 110105555961.

It is an arithmetic number, because the mean of its divisors is an integer number (110105555961).

Almost surely, 2^220211111921 is an apocalyptic number.

It is an amenable number.

220211111921 is a deficient number, since it is larger than the sum of its proper divisors (1).

220211111921 is an equidigital number, since it uses as much as digits as its factorization.

220211111921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 23.

Adding to 220211111921 its reverse (129111112022), we get a palindrome (349322223943).

The spelling of 220211111921 in words is "two hundred twenty billion, two hundred eleven million, one hundred eleven thousand, nine hundred twenty-one".