442639 has 4 divisors (see below), whose sum is σ = 448056. Its totient is φ = 437224.

The previous prime is 442633. The next prime is 442691. The reversal of 442639 is 936244.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 442639 - 2¹⁷ = 311567 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (442633) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2584 + ... + 2749.

It is an arithmetic number, because the mean of its divisors is an integer number (112014).

2⁴⁴²⁶³⁹ is an apocalyptic number.

442639 is a deficient number, since it is larger than the sum of its proper divisors (5417).

442639 is an equidigital number, since it uses as much as digits as its factorization.

442639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5416.

The product of its digits is 5184, while the sum is 28.

The square root of 442639 is about 665.3112053769. The cubic root of 442639 is about 76.2108066963.

It can be divided in two parts, 4426 and 39, that added together give a triangular number (4465 = T₉₄).

The spelling of 442639 in words is "four hundred forty-two thousand, six hundred thirty-nine".