6434640 has 120 divisors (see below), whose sum is σ = 22477728. Its totient is φ = 1710720.

The previous prime is 6434627. The next prime is 6434647. The reversal of 6434640 is 464346.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6434647) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19275 + ... + 19605.

Almost surely, 2^6434640 is an apocalyptic number.

6434640 is a gapful number since it is divisible by the number (60) 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 6434640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11238864).

6434640 is an abundant number, since it is smaller than the sum of its proper divisors (16043088).

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

6434640 is a wasteful number, since it uses less digits than its factorization.

6434640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359 (or 341 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 6434640 is about 2536.6592203132. The cubic root of 6434640 is about 185.9979188113.

Adding to 6434640 its reverse (464346), we get a palindrome (6898986).

The spelling of 6434640 in words is "six million, four hundred thirty-four thousand, six hundred forty".