42004409 has 2 divisors, whose sum is σ = 42004410. Its totient is φ = 42004408.

The previous prime is 42004397. The next prime is 42004423. The reversal of 42004409 is 90440024.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25030009 + 16974400 = 5003^2 + 4120^2 .

It is a cyclic number.

It is not a de Polignac number, because 42004409 - 2⁴ = 42004393 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (42004429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21002204 + 21002205.

It is an arithmetic number, because the mean of its divisors is an integer number (21002205).

Almost surely, 2^42004409 is an apocalyptic number.

It is an amenable number.

42004409 is a deficient number, since it is larger than the sum of its proper divisors (1).

42004409 is an equidigital number, since it uses as much as digits as its factorization.

42004409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 42004409 is about 6481.0808512161. The cubic root of 42004409 is about 347.6148273976.

The spelling of 42004409 in words is "forty-two million, four thousand, four hundred nine".