42173521 has 16 divisors (see below), whose sum is σ = 48263040. Its totient is φ = 36529920.

The previous prime is 42173519. The next prime is 42173533. The reversal of 42173521 is 12537124.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 42173521 - 2¹ = 42173519 is a prime.

It is not an unprimeable number, because it can be changed into a prime (42173501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27156 + ... + 28666.

It is an arithmetic number, because the mean of its divisors is an integer number (3016440).

Almost surely, 2^42173521 is an apocalyptic number.

It is an amenable number.

42173521 is a deficient number, since it is larger than the sum of its proper divisors (6089519).

42173521 is a wasteful number, since it uses less digits than its factorization.

42173521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1656.

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

The square root of 42173521 is about 6494.1143353039. The cubic root of 42173521 is about 348.0807080390.

The spelling of 42173521 in words is "forty-two million, one hundred seventy-three thousand, five hundred twenty-one".