42043521 has 16 divisors (see below), whose sum is σ = 61657344. Its totient is φ = 25321344.

The previous prime is 42043513. The next prime is 42043531. The reversal of 42043521 is 12534024.

It is not a de Polignac number, because 42043521 - 2³ = 42043513 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (42043531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9636 + ... + 13301.

It is an arithmetic number, because the mean of its divisors is an integer number (3853584).

Almost surely, 2^42043521 is an apocalyptic number.

It is an amenable number.

42043521 is a deficient number, since it is larger than the sum of its proper divisors (19613823).

42043521 is a wasteful number, since it uses less digits than its factorization.

42043521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23000.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 42043521 is about 6484.0975470762. The cubic root of 42043521 is about 347.7226866575.

Adding to 42043521 its reverse (12534024), we get a palindrome (54577545).

The spelling of 42043521 in words is "forty-two million, forty-three thousand, five hundred twenty-one".