442640 has 40 divisors (see below), whose sum is σ = 1124928. Its totient is φ = 160640.

The previous prime is 442633. The next prime is 442691. The reversal of 442640 is 46244.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 629 + ... + 1131.

2⁴⁴²⁶⁴⁰ is an apocalyptic number.

442640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 442640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (562464).

442640 is an abundant number, since it is smaller than the sum of its proper divisors (682288).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

442640 is a wasteful number, since it uses less digits than its factorization.

442640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 527 (or 521 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 442640 is about 665.3119569044. The cubic root of 442640 is about 76.2108640875.

Adding to 442640 its reverse (46244), we get a palindrome (488884).

The spelling of 442640 in words is "four hundred forty-two thousand, six hundred forty".