2043521021 has 2 divisors, whose sum is σ = 2043521022. Its totient is φ = 2043521020.

The previous prime is 2043521017. The next prime is 2043521083. The reversal of 2043521021 is 1201253402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1248844921 + 794676100 = 35339^2 + 28190^2 .

It is a cyclic number.

It is not a de Polignac number, because 2043521021 - 2² = 2043521017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2043520984 and 2043521002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2043521321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1021760510 + 1021760511.

It is an arithmetic number, because the mean of its divisors is an integer number (1021760511).

Almost surely, 2^2043521021 is an apocalyptic number.

It is an amenable number.

2043521021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2043521021 is an equidigital number, since it uses as much as digits as its factorization.

2043521021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 2043521021 is about 45205.3207155972. The cubic root of 2043521021 is about 1268.9943929509.

Adding to 2043521021 its reverse (1201253402), we get a palindrome (3244774423).

The spelling of 2043521021 in words is "two billion, forty-three million, five hundred twenty-one thousand, twenty-one".