6406561 has 4 divisors (see below), whose sum is σ = 7321792. Its totient is φ = 5491332.

The previous prime is 6406549. The next prime is 6406571. The reversal of 6406561 is 1656046.

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 6406561 - 2⁵ = 6406529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6406571) 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, 457605 + ... + 457618.

It is an arithmetic number, because the mean of its divisors is an integer number (1830448).

Almost surely, 2^6406561 is an apocalyptic number.

It is an amenable number.

6406561 is a deficient number, since it is larger than the sum of its proper divisors (915231).

6406561 is an equidigital number, since it uses as much as digits as its factorization.

6406561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 915230.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 6406561 is about 2531.1185274499. The cubic root of 6406561 is about 185.7269763940.

The spelling of 6406561 in words is "six million, four hundred six thousand, five hundred sixty-one".