6440247 has 12 divisors (see below), whose sum is σ = 10148424. Its totient is φ = 3903120.

The previous prime is 6440201. The next prime is 6440249. The reversal of 6440247 is 7420446.

It is not a de Polignac number, because 6440247 - 2¹¹ = 6438199 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

6440247 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 6440247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6440249) 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 11 ways as a sum of consecutive naturals, for example, 32428 + ... + 32625.

It is an arithmetic number, because the mean of its divisors is an integer number (845702).

Almost surely, 2^6440247 is an apocalyptic number.

6440247 is a deficient number, since it is larger than the sum of its proper divisors (3708177).

6440247 is a wasteful number, since it uses less digits than its factorization.

6440247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65070 (or 65067 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 27.

The square root of 6440247 is about 2537.7641734409. The cubic root of 6440247 is about 186.0519279224.

The spelling of 6440247 in words is "six million, four hundred forty thousand, two hundred forty-seven".