440639 has 4 divisors (see below), whose sum is σ = 445680. Its totient is φ = 435600.

The previous prime is 440581. The next prime is 440641. The reversal of 440639 is 936044.

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 440639 - 2⁸ = 440383 is a prime.

It is a super-3 number, since 3×440639³ = 256667011333911357, which contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (440669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2387 + ... + 2564.

It is an arithmetic number, because the mean of its divisors is an integer number (111420).

2⁴⁴⁰⁶³⁹ is an apocalyptic number.

440639 is a deficient number, since it is larger than the sum of its proper divisors (5041).

440639 is an equidigital number, since it uses as much as digits as its factorization.

440639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5040.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 440639 is about 663.8064476939. The cubic root of 440639 is about 76.0958508999.

The spelling of 440639 in words is "four hundred forty thousand, six hundred thirty-nine".