42056009 has 2 divisors, whose sum is σ = 42056010. Its totient is φ = 42056008.

The previous prime is 42055997. The next prime is 42056041. The reversal of 42056009 is 90065024.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42055225 + 784 = 6485^2 + 28^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42056009 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (42056059) 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 as a sum of consecutive naturals, namely, 21028004 + 21028005.

It is an arithmetic number, because the mean of its divisors is an integer number (21028005).

Almost surely, 2^42056009 is an apocalyptic number.

It is an amenable number.

42056009 is a deficient number, since it is larger than the sum of its proper divisors (1).

42056009 is an equidigital number, since it uses as much as digits as its factorization.

42056009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 42056009 is about 6485.0604469041. The cubic root of 42056009 is about 347.7571107570.

The spelling of 42056009 in words is "forty-two million, fifty-six thousand, nine".