6440899 has 4 divisors (see below), whose sum is σ = 6503536. Its totient is φ = 6378264.

The previous prime is 6440893. The next prime is 6440933. The reversal of 6440899 is 9980446.

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 6440899 - 2³ = 6440891 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (6440891) 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, 31164 + ... + 31369.

It is an arithmetic number, because the mean of its divisors is an integer number (1625884).

Almost surely, 2^6440899 is an apocalyptic number.

6440899 is a deficient number, since it is larger than the sum of its proper divisors (62637).

6440899 is a wasteful number, since it uses less digits than its factorization.

6440899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62636.

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 6440899 is about 2537.8926297225. The cubic root of 6440899 is about 186.0582062408.

The spelling of 6440899 in words is "six million, four hundred forty thousand, eight hundred ninety-nine".