6645687 has 16 divisors (see below), whose sum is σ = 9630720. Its totient is φ = 4060800.

The previous prime is 6645679. The next prime is 6645697. The reversal of 6645687 is 7865466.

It is a happy number.

It is not a de Polignac number, because 6645687 - 2³ = 6645679 is a prime.

It is an Ulam number.

6645687 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6645637) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 114 + ... + 3647.

It is an arithmetic number, because the mean of its divisors is an integer number (601920).

Almost surely, 2^6645687 is an apocalyptic number.

6645687 is a deficient number, since it is larger than the sum of its proper divisors (2985033).

6645687 is a wasteful number, since it uses less digits than its factorization.

6645687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3814.

The product of its digits is 241920, while the sum is 42.

The square root of 6645687 is about 2577.9230011775. The cubic root of 6645687 is about 188.0095720945.

It can be divided in two parts, 66 and 45687, that added together give a triangular number (45753 = T₃₀₂).

The spelling of 6645687 in words is "six million, six hundred forty-five thousand, six hundred eighty-seven".