42084209 has 4 divisors (see below), whose sum is σ = 42219840. Its totient is φ = 41948580.

The previous prime is 42084193. The next prime is 42084233. The reversal of 42084209 is 90248024.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 42084209 - 2⁴ = 42084193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42084239) 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, 67349 + ... + 67970.

It is an arithmetic number, because the mean of its divisors is an integer number (10554960).

Almost surely, 2^42084209 is an apocalyptic number.

It is an amenable number.

42084209 is a deficient number, since it is larger than the sum of its proper divisors (135631).

42084209 is a wasteful number, since it uses less digits than its factorization.

42084209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135630.

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 42084209 is about 6487.2343105518. The cubic root of 42084209 is about 347.8348210902.

The spelling of 42084209 in words is "forty-two million, eighty-four thousand, two hundred nine".