6442509 has 4 divisors (see below), whose sum is σ = 8590016. Its totient is φ = 4295004.

The previous prime is 6442493. The next prime is 6442531. The reversal of 6442509 is 9052446.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 6442509 - 2⁴ = 6442493 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6442559) 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, 1073749 + ... + 1073754.

It is an arithmetic number, because the mean of its divisors is an integer number (2147504).

Almost surely, 2^6442509 is an apocalyptic number.

It is an amenable number.

6442509 is a deficient number, since it is larger than the sum of its proper divisors (2147507).

6442509 is a wasteful number, since it uses less digits than its factorization.

6442509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2147506.

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 6442509 is about 2538.2098022031. The cubic root of 6442509 is about 186.0737076356.

The spelling of 6442509 in words is "six million, four hundred forty-two thousand, five hundred nine".