211202220220021 has 4 divisors (see below), whose sum is σ = 211202257856652. Its totient is φ = 211202182583392.

The previous prime is 211202220220001. The next prime is 211202220220051. The reversal of 211202220220021 is 120022022202112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 166946064819121 + 44256155400900 = 12920761^2 + 6652530^2 .

It is a cyclic number.

It is not a de Polignac number, because 211202220220021 - 2³⁹ = 210652464406133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211202220220001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8523640 + ... + 22249873.

It is an arithmetic number, because the mean of its divisors is an integer number (52800564464163).

Almost surely, 2^{211202220220021} is an apocalyptic number.

It is an amenable number.

211202220220021 is a deficient number, since it is larger than the sum of its proper divisors (37636631).

211202220220021 is an equidigital number, since it uses as much as digits as its factorization.

211202220220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37636630.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 211202220220021 its reverse (120022022202112), we get a palindrome (331224242422133).

The spelling of 211202220220021 in words is "two hundred eleven trillion, two hundred two billion, two hundred twenty million, two hundred twenty thousand, twenty-one".