6640636 has 12 divisors (see below), whose sum is σ = 11656512. Its totient is φ = 3310208.

The previous prime is 6640631. The next prime is 6640639. The reversal of 6640636 is 6360466.

It is a junction number, because it is equal to n+sod(n) for n = 6640598 and 6640607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640631) 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, 940 + ... + 3763.

It is an arithmetic number, because the mean of its divisors is an integer number (971376).

Almost surely, 2^6640636 is an apocalyptic number.

It is an amenable number.

6640636 is a deficient number, since it is larger than the sum of its proper divisors (5015876).

6640636 is a wasteful number, since it uses less digits than its factorization.

6640636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5060 (or 5058 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 31.

The square root of 6640636 is about 2576.9431503237. The cubic root of 6640636 is about 187.9619283100.

The spelling of 6640636 in words is "six million, six hundred forty thousand, six hundred thirty-six".