6640520 has 16 divisors (see below), whose sum is σ = 14941260. Its totient is φ = 2656192.

The previous prime is 6640511. The next prime is 6640547. The reversal of 6640520 is 250466.

It can be written as a sum of positive squares in 2 ways, for example, as 6482116 + 158404 = 2546^2 + 398^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82967 + ... + 83046.

Almost surely, 2^6640520 is an apocalyptic number.

It is an amenable number.

6640520 is an abundant number, since it is smaller than the sum of its proper divisors (8300740).

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

6640520 is a wasteful number, since it uses less digits than its factorization.

6640520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166024 (or 166020 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 6640520 is about 2576.9206429380. The cubic root of 6640520 is about 187.9608338510.

Adding to 6640520 its reverse (250466), we get a palindrome (6890986).

The spelling of 6640520 in words is "six million, six hundred forty thousand, five hundred twenty".