2121220020021 has 4 divisors (see below), whose sum is σ = 2828293360032. Its totient is φ = 1414146680012.

The previous prime is 2121220019987. The next prime is 2121220020041. The reversal of 2121220020021 is 1200200221212.

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 2121220020021 - 2¹³ = 2121220011829 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121220020041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 353536670001 + ... + 353536670006.

It is an arithmetic number, because the mean of its divisors is an integer number (707073340008).

Almost surely, 2^{2121220020021} is an apocalyptic number.

It is an amenable number.

2121220020021 is a deficient number, since it is larger than the sum of its proper divisors (707073340011).

2121220020021 is an equidigital number, since it uses as much as digits as its factorization.

2121220020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 707073340010.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 2121220020021 its reverse (1200200221212), we get a palindrome (3321420241233).

The spelling of 2121220020021 in words is "two trillion, one hundred twenty-one billion, two hundred twenty million, twenty thousand, twenty-one".