42004121521 has 2 divisors, whose sum is σ = 42004121522. Its totient is φ = 42004121520.

The previous prime is 42004121483. The next prime is 42004121567. The reversal of 42004121521 is 12512140024.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40401000000 + 1603121521 = 201000^2 + 40039^2 .

It is a cyclic number.

It is not a de Polignac number, because 42004121521 - 2¹¹ = 42004119473 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 42004121492 and 42004121501.

It is not a weakly prime, because it can be changed into another prime (42004121021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21002060760 + 21002060761.

It is an arithmetic number, because the mean of its divisors is an integer number (21002060761).

Almost surely, 2^42004121521 is an apocalyptic number.

It is an amenable number.

42004121521 is a deficient number, since it is larger than the sum of its proper divisors (1).

42004121521 is an equidigital number, since it uses as much as digits as its factorization.

42004121521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 640, while the sum is 22.

Adding to 42004121521 its reverse (12512140024), we get a palindrome (54516261545).

The spelling of 42004121521 in words is "forty-two billion, four million, one hundred twenty-one thousand, five hundred twenty-one".