6640645 has 8 divisors (see below), whose sum is σ = 8693280. Its totient is φ = 4829520.

The previous prime is 6640639. The next prime is 6640651. The reversal of 6640645 is 5460466.

It is an interprime number because it is at equal distance from previous prime (6640639) and next prime (6640651).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-6640645 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60315 + ... + 60424.

It is an arithmetic number, because the mean of its divisors is an integer number (1086660).

Almost surely, 2^6640645 is an apocalyptic number.

It is an amenable number.

6640645 is a deficient number, since it is larger than the sum of its proper divisors (2052635).

6640645 is a wasteful number, since it uses less digits than its factorization.

6640645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120755.

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 6640645 is about 2576.9448965781. The cubic root of 6640645 is about 187.9620132244.

The spelling of 6640645 in words is "six million, six hundred forty thousand, six hundred forty-five".