6432640 has 96 divisors (see below), whose sum is σ = 16921800. Its totient is φ = 2331648.

The previous prime is 6432637. The next prime is 6432649. The reversal of 6432640 is 462346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6432649) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 279669 + ... + 279691.

Almost surely, 2^6432640 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 6432640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8460900).

6432640 is an abundant number, since it is smaller than the sum of its proper divisors (10489160).

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

6432640 is a wasteful number, since it uses less digits than its factorization.

6432640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84 (or 49 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 6432640 is about 2536.2649703846. The cubic root of 6432640 is about 185.9786463327.

Adding to 6432640 its reverse (462346), we get a palindrome (6894986).

The spelling of 6432640 in words is "six million, four hundred thirty-two thousand, six hundred forty".