42521173 has 4 divisors (see below), whose sum is σ = 42806700. Its totient is φ = 42235648.

The previous prime is 42521161. The next prime is 42521179. The reversal of 42521173 is 37112524.

It is a happy number.

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 1855044 + 40666129 = 1362^2 + 6377^2 .

It is a cyclic number.

It is not a de Polignac number, because 42521173 - 2⁹ = 42520661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42521179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142540 + ... + 142837.

It is an arithmetic number, because the mean of its divisors is an integer number (10701675).

Almost surely, 2^42521173 is an apocalyptic number.

It is an amenable number.

42521173 is a deficient number, since it is larger than the sum of its proper divisors (285527).

42521173 is a wasteful number, since it uses less digits than its factorization.

42521173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285526.

The product of its digits is 1680, while the sum is 25.

The square root of 42521173 is about 6520.8260979726. The cubic root of 42521173 is about 349.0345447370.

Adding to 42521173 its reverse (37112524), we get a palindrome (79633697).

The spelling of 42521173 in words is "forty-two million, five hundred twenty-one thousand, one hundred seventy-three".