42043452421 has 4 divisors (see below), whose sum is σ = 42069137292. Its totient is φ = 42017767552.

The previous prime is 42043452391. The next prime is 42043452443. The reversal of 42043452421 is 12425434024.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 519201796 + 41524250625 = 22786^2 + 203775^2 .

It is a cyclic number.

It is not a de Polignac number, because 42043452421 - 2¹¹ = 42043450373 is a prime.

It is a super-2 number, since 2×42043452421² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42043852421) 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 in 3 ways as a sum of consecutive naturals, for example, 12839980 + ... + 12843253.

It is an arithmetic number, because the mean of its divisors is an integer number (10517284323).

Almost surely, 2^42043452421 is an apocalyptic number.

It is an amenable number.

42043452421 is a deficient number, since it is larger than the sum of its proper divisors (25684871).

42043452421 is a wasteful number, since it uses less digits than its factorization.

42043452421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25684870.

The product of its (nonzero) digits is 30720, while the sum is 31.

Adding to 42043452421 its reverse (12425434024), we get a palindrome (54468886445).

The spelling of 42043452421 in words is "forty-two billion, forty-three million, four hundred fifty-two thousand, four hundred twenty-one".