211121022020021 has 4 divisors (see below), whose sum is σ = 214699344427200. Its totient is φ = 207542699612844.

The previous prime is 211121022020011. The next prime is 211121022020093. The reversal of 211121022020021 is 120020220121112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 211121022020021 - 2¹⁴ = 211121022003637 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 (211121022020011) 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, 1789161203501 + ... + 1789161203618.

It is an arithmetic number, because the mean of its divisors is an integer number (53674836106800).

Almost surely, 2^{211121022020021} is an apocalyptic number.

It is an amenable number.

211121022020021 is a deficient number, since it is larger than the sum of its proper divisors (3578322407179).

211121022020021 is an equidigital number, since it uses as much as digits as its factorization.

211121022020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3578322407178.

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

Adding to 211121022020021 its reverse (120020220121112), we get a palindrome (331141242141133).

The spelling of 211121022020021 in words is "two hundred eleven trillion, one hundred twenty-one billion, twenty-two million, twenty thousand, twenty-one".