4042123021 has 2 divisors, whose sum is σ = 4042123022. Its totient is φ = 4042123020.

The previous prime is 4042123013. The next prime is 4042123049. The reversal of 4042123021 is 1203212404.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4041144900 + 978121 = 63570^2 + 989^2 .

It is a cyclic number.

It is not a de Polignac number, because 4042123021 - 2³ = 4042123013 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 4042123021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4042123051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2021061510 + 2021061511.

It is an arithmetic number, because the mean of its divisors is an integer number (2021061511).

Almost surely, 2^4042123021 is an apocalyptic number.

It is an amenable number.

4042123021 is a deficient number, since it is larger than the sum of its proper divisors (1).

4042123021 is an equidigital number, since it uses as much as digits as its factorization.

4042123021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 4042123021 is about 63577.6927939352. The cubic root of 4042123021 is about 1592.9537831791.

Adding to 4042123021 its reverse (1203212404), we get a palindrome (5245335425).

The spelling of 4042123021 in words is "four billion, forty-two million, one hundred twenty-three thousand, twenty-one".