6640229 has 4 divisors (see below), whose sum is σ = 6647820. Its totient is φ = 6632640.

The previous prime is 6640223. The next prime is 6640241. The reversal of 6640229 is 9220466.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1809025 + 4831204 = 1345^2 + 2198^2 .

It is a cyclic number.

It is not a de Polignac number, because 6640229 - 2⁴ = 6640213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2282 + ... + 4299.

It is an arithmetic number, because the mean of its divisors is an integer number (1661955).

Almost surely, 2^6640229 is an apocalyptic number.

It is an amenable number.

6640229 is a deficient number, since it is larger than the sum of its proper divisors (7591).

6640229 is a wasteful number, since it uses less digits than its factorization.

6640229 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7590.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 6640229 is about 2576.8641795795. The cubic root of 6640229 is about 187.9580882125.

The spelling of 6640229 in words is "six million, six hundred forty thousand, two hundred twenty-nine".