202221201220021 has 4 divisors (see below), whose sum is σ = 202223957514700. Its totient is φ = 202218444925344.

The previous prime is 202221201219907. The next prime is 202221201220037. The reversal of 202221201220021 is 120022102122202.

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 65470980519396 + 136750220700625 = 8091414^2 + 11694025^2 .

It is a cyclic number.

It is not a de Polignac number, because 202221201220021 - 2³⁷ = 202083762266549 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 (202221202220021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1378037286 + ... + 1378184023.

It is an arithmetic number, because the mean of its divisors is an integer number (50555989378675).

Almost surely, 2^{202221201220021} is an apocalyptic number.

It is an amenable number.

202221201220021 is a deficient number, since it is larger than the sum of its proper divisors (2756294679).

202221201220021 is an equidigital number, since it uses as much as digits as its factorization.

202221201220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2756294678.

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

Adding to 202221201220021 its reverse (120022102122202), we get a palindrome (322243303342223).

The spelling of 202221201220021 in words is "two hundred two trillion, two hundred twenty-one billion, two hundred one million, two hundred twenty thousand, twenty-one".