42021224521 has 2 divisors, whose sum is σ = 42021224522. Its totient is φ = 42021224520.

The previous prime is 42021224519. The next prime is 42021224561. The reversal of 42021224521 is 12542212024.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31853325625 + 10167898896 = 178475^2 + 100836^2 .

It is a cyclic number.

It is not a de Polignac number, because 42021224521 - 2¹ = 42021224519 is a prime.

Together with 42021224519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (42021224561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21010612260 + 21010612261.

It is an arithmetic number, because the mean of its divisors is an integer number (21010612261).

Almost surely, 2^42021224521 is an apocalyptic number.

It is an amenable number.

42021224521 is a deficient number, since it is larger than the sum of its proper divisors (1).

42021224521 is an equidigital number, since it uses as much as digits as its factorization.

42021224521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2560, while the sum is 25.

Adding to 42021224521 its reverse (12542212024), we get a palindrome (54563436545).

The spelling of 42021224521 in words is "forty-two billion, twenty-one million, two hundred twenty-four thousand, five hundred twenty-one".