2121112220021 has 4 divisors (see below), whose sum is σ = 2121632232000. Its totient is φ = 2120592208044.

The previous prime is 2121112220011. The next prime is 2121112220041. The reversal of 2121112220021 is 1200222111212.

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 2121112220021 - 2⁶ = 2121112219957 is a prime.

It is a super-2 number, since 2×2121112220021² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121112220011) 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, 259999871 + ... + 260008028.

It is an arithmetic number, because the mean of its divisors is an integer number (530408058000).

Almost surely, 2^{2121112220021} is an apocalyptic number.

It is an amenable number.

2121112220021 is a deficient number, since it is larger than the sum of its proper divisors (520011979).

2121112220021 is an equidigital number, since it uses as much as digits as its factorization.

2121112220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520011978.

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

Adding to 2121112220021 its reverse (1200222111212), we get a palindrome (3321334331233).

The spelling of 2121112220021 in words is "two trillion, one hundred twenty-one billion, one hundred twelve million, two hundred twenty thousand, twenty-one".