6516409 has 4 divisors (see below), whose sum is σ = 6655104. Its totient is φ = 6377716.

The previous prime is 6516401. The next prime is 6516421. The reversal of 6516409 is 9046156.

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 a cyclic number.

It is not a de Polignac number, because 6516409 - 2³ = 6516401 is a prime.

It is a Duffinian number.

6516409 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6516401) 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, 69277 + ... + 69370.

It is an arithmetic number, because the mean of its divisors is an integer number (1663776).

Almost surely, 2^6516409 is an apocalyptic number.

It is an amenable number.

6516409 is a deficient number, since it is larger than the sum of its proper divisors (138695).

6516409 is a wasteful number, since it uses less digits than its factorization.

6516409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138694.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 6516409 is about 2552.7257980441. The cubic root of 6516409 is about 186.7824688905.

The spelling of 6516409 in words is "six million, five hundred sixteen thousand, four hundred nine".