2121221021 has 4 divisors (see below), whose sum is σ = 2148072000. Its totient is φ = 2094370044.

The previous prime is 2121221017. The next prime is 2121221051. The reversal of 2121221021 is 1201221212.

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 2121221021 - 2² = 2121221017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121220987 and 2121221005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121221051) 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, 13425371 + ... + 13425528.

It is an arithmetic number, because the mean of its divisors is an integer number (537018000).

Almost surely, 2^2121221021 is an apocalyptic number.

It is an amenable number.

2121221021 is a deficient number, since it is larger than the sum of its proper divisors (26850979).

2121221021 is an equidigital number, since it uses as much as digits as its factorization.

2121221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26850978.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 2121221021 is about 46056.7152649861. The cubic root of 2121221021 is about 1284.8782396603.

Adding to 2121221021 its reverse (1201221212), we get a palindrome (3322442233).

The spelling of 2121221021 in words is "two billion, one hundred twenty-one million, two hundred twenty-one thousand, twenty-one".