6406689 has 4 divisors (see below), whose sum is σ = 8542256. Its totient is φ = 4271124.

The previous prime is 6406681. The next prime is 6406691. The reversal of 6406689 is 9866046.

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 6406689 - 2³ = 6406681 is a prime.

It is an Ulam number.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

6406689 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6406681) 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, 1067779 + ... + 1067784.

It is an arithmetic number, because the mean of its divisors is an integer number (2135564).

Almost surely, 2^6406689 is an apocalyptic number.

It is an amenable number.

6406689 is a deficient number, since it is larger than the sum of its proper divisors (2135567).

6406689 is a wasteful number, since it uses less digits than its factorization.

6406689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2135566.

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 6406689 is about 2531.1438125875. The cubic root of 6406689 is about 185.7282132975.

The spelling of 6406689 in words is "six million, four hundred six thousand, six hundred eighty-nine".