2121223021 has 4 divisors (see below), whose sum is σ = 2121541632. Its totient is φ = 2120904412.

The previous prime is 2121223003. The next prime is 2121223031. The reversal of 2121223021 is 1203221212.

It is a happy number.

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 2121223021 - 2⁵ = 2121222989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121222986 and 2121223004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121223031) 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, 149101 + ... + 162706.

It is an arithmetic number, because the mean of its divisors is an integer number (530385408).

Almost surely, 2^2121223021 is an apocalyptic number.

It is an amenable number.

2121223021 is a deficient number, since it is larger than the sum of its proper divisors (318611).

2121223021 is an equidigital number, since it uses as much as digits as its factorization.

2121223021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318610.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 2121223021 is about 46056.7369773413. The cubic root of 2121223021 is about 1284.8786434773.

Adding to 2121223021 its reverse (1203221212), we get a palindrome (3324444233).

The spelling of 2121223021 in words is "two billion, one hundred twenty-one million, two hundred twenty-three thousand, twenty-one".