42004521 has 16 divisors (see below), whose sum is σ = 67016320. Its totient is φ = 25848720.

The previous prime is 42004517. The next prime is 42004531. The reversal of 42004521 is 12540024.

It is not a de Polignac number, because 42004521 - 2² = 42004517 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 42004494 and 42004503.

It is not an unprimeable number, because it can be changed into a prime (42004531) 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, 59485 + ... + 60186.

It is an arithmetic number, because the mean of its divisors is an integer number (4188520).

Almost surely, 2^42004521 is an apocalyptic number.

It is an amenable number.

42004521 is a deficient number, since it is larger than the sum of its proper divisors (25011799).

42004521 is a wasteful number, since it uses less digits than its factorization.

42004521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119693 (or 119687 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 42004521 is about 6481.0894917444. The cubic root of 42004521 is about 347.6151363558.

Adding to 42004521 its reverse (12540024), we get a palindrome (54544545).

The spelling of 42004521 in words is "forty-two million, four thousand, five hundred twenty-one".