4243633021 has 2 divisors, whose sum is σ = 4243633022. Its totient is φ = 4243633020.

The previous prime is 4243633019. The next prime is 4243633157. The reversal of 4243633021 is 1203363424.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2498900121 + 1744732900 = 49989^2 + 41770^2 .

It is a cyclic number.

It is not a de Polignac number, because 4243633021 - 2¹ = 4243633019 is a prime.

Together with 4243633019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4243633921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2121816510 + 2121816511.

It is an arithmetic number, because the mean of its divisors is an integer number (2121816511).

Almost surely, 2^4243633021 is an apocalyptic number.

It is an amenable number.

4243633021 is a deficient number, since it is larger than the sum of its proper divisors (1).

4243633021 is an equidigital number, since it uses as much as digits as its factorization.

4243633021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 28.

The square root of 4243633021 is about 65143.1732493897. The cubic root of 4243633021 is about 1618.9966124355.

Adding to 4243633021 its reverse (1203363424), we get a palindrome (5446996445).

It can be divided in two parts, 42436 and 33021, that added together give a palindrome (75457).

The spelling of 4243633021 in words is "four billion, two hundred forty-three million, six hundred thirty-three thousand, twenty-one".