6442540 has 48 divisors (see below), whose sum is σ = 14817600. Its totient is φ = 2338560.

The previous prime is 6442531. The next prime is 6442559. The reversal of 6442540 is 452446.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18286 + ... + 18634.

It is an arithmetic number, because the mean of its divisors is an integer number (308700).

Almost surely, 2^6442540 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6442540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7408800).

6442540 is an abundant number, since it is smaller than the sum of its proper divisors (8375060).

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

6442540 is a wasteful number, since it uses less digits than its factorization.

6442540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442 (or 440 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 25.

The square root of 6442540 is about 2538.2159088620. The cubic root of 6442540 is about 186.0740060844.

Adding to 6442540 its reverse (452446), we get a palindrome (6894986).

The spelling of 6442540 in words is "six million, four hundred forty-two thousand, five hundred forty".