6645257 has 4 divisors (see below), whose sum is σ = 6656916. Its totient is φ = 6633600.

The previous prime is 6645227. The next prime is 6645259. The reversal of 6645257 is 7525466.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3444736 + 3200521 = 1856^2 + 1789^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6645257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6645259) 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, 4928 + ... + 6129.

It is an arithmetic number, because the mean of its divisors is an integer number (1664229).

Almost surely, 2^6645257 is an apocalyptic number.

It is an amenable number.

6645257 is a deficient number, since it is larger than the sum of its proper divisors (11659).

6645257 is a wasteful number, since it uses less digits than its factorization.

6645257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11658.

The product of its digits is 50400, while the sum is 35.

The square root of 6645257 is about 2577.8395993545. The cubic root of 6645257 is about 188.0055170404.

The spelling of 6645257 in words is "six million, six hundred forty-five thousand, two hundred fifty-seven".