6440207 has 4 divisors (see below), whose sum is σ = 6720240. Its totient is φ = 6160176.

The previous prime is 6440201. The next prime is 6440249. The reversal of 6440207 is 7020446.

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

It is a cyclic number.

It is not a de Polignac number, because 6440207 - 2⁴ = 6440191 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 280009 = 6440207 / (6 + 4 + 4 + 0 + 2 + 0 + 7).

It is a Duffinian number.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6440201) 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, 139982 + ... + 140027.

It is an arithmetic number, because the mean of its divisors is an integer number (1680060).

Almost surely, 2^6440207 is an apocalyptic number.

6440207 is a deficient number, since it is larger than the sum of its proper divisors (280033).

6440207 is a wasteful number, since it uses less digits than its factorization.

6440207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280032.

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 6440207 is about 2537.7562924757. The cubic root of 6440207 is about 186.0515427357.

The spelling of 6440207 in words is "six million, four hundred forty thousand, two hundred seven".