2121442021 has 2 divisors, whose sum is σ = 2121442022. Its totient is φ = 2121442020.

The previous prime is 2121442013. The next prime is 2121442033. The reversal of 2121442021 is 1202441212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1473484996 + 647957025 = 38386^2 + 25455^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121442021 - 2³ = 2121442013 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2121442021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121442051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060721010 + 1060721011.

It is an arithmetic number, because the mean of its divisors is an integer number (1060721011).

Almost surely, 2^2121442021 is an apocalyptic number.

It is an amenable number.

2121442021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121442021 is an equidigital number, since it uses as much as digits as its factorization.

2121442021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 2121442021 is about 46059.1144183212. The cubic root of 2121442021 is about 1284.9228599092.

Adding to 2121442021 its reverse (1202441212), we get a palindrome (3323883233).

The spelling of 2121442021 in words is "two billion, one hundred twenty-one million, four hundred forty-two thousand, twenty-one".