442009 has 2 divisors, whose sum is σ = 442010. Its totient is φ = 442008.

The previous prime is 442007. The next prime is 442019. The reversal of 442009 is 900244.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 363609 + 78400 = 603^2 + 280^2 .

It is a cyclic number.

It is not a de Polignac number, because 442009 - 2¹ = 442007 is a prime.

Together with 442007, it forms a pair of twin primes.

442009 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (442003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 221004 + 221005.

It is an arithmetic number, because the mean of its divisors is an integer number (221005).

2⁴⁴²⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

442009 is a deficient number, since it is larger than the sum of its proper divisors (1).

442009 is an equidigital number, since it uses as much as digits as its factorization.

442009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 442009 is about 664.8375741488. The cubic root of 442009 is about 76.1746330463.

The spelling of 442009 in words is "four hundred forty-two thousand, nine".