6486640 has 20 divisors (see below), whose sum is σ = 15081624. Its totient is φ = 2594624.

The previous prime is 6486629. The next prime is 6486647. The reversal of 6486640 is 466846.

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 6486596 and 6486605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6486647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40462 + ... + 40621.

Almost surely, 2^6486640 is an apocalyptic number.

It is an amenable number.

6486640 is an abundant number, since it is smaller than the sum of its proper divisors (8594984).

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

6486640 is a wasteful number, since it uses less digits than its factorization.

6486640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81096 (or 81090 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 34.

The square root of 6486640 is about 2546.8882975113. Note that the first 3 decimals coincide. The cubic root of 6486640 is about 186.4976077051.

The spelling of 6486640 in words is "six million, four hundred eighty-six thousand, six hundred forty".