6644681 has 2 divisors, whose sum is σ = 6644682. Its totient is φ = 6644680.

The previous prime is 6644647. The next prime is 6644717. The reversal of 6644681 is 1864466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5216656 + 1428025 = 2284^2 + 1195^2 .

It is a cyclic number.

It is not a de Polignac number, because 6644681 - 2²² = 2450377 is a prime.

It is a super-2 number, since 2×6644681² = 88303571183522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (6644621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3322340 + 3322341.

It is an arithmetic number, because the mean of its divisors is an integer number (3322341).

Almost surely, 2^6644681 is an apocalyptic number.

It is an amenable number.

6644681 is a deficient number, since it is larger than the sum of its proper divisors (1).

6644681 is an equidigital number, since it uses as much as digits as its factorization.

6644681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27648, while the sum is 35.

The square root of 6644681 is about 2577.7278754748. The cubic root of 6644681 is about 188.0000848800. Note that the first 4 decimals are identical.

The spelling of 6644681 in words is "six million, six hundred forty-four thousand, six hundred eighty-one".