6409999 has 4 divisors (see below), whose sum is σ = 6472336. Its totient is φ = 6347664.

The previous prime is 6409943. The next prime is 6410009. The reversal of 6409999 is 9999046.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9999046 = 2 ⋅4999523.

It is a cyclic number.

It is not a de Polignac number, because 6409999 - 2¹⁷ = 6278927 is a prime.

It is a Duffinian number.

6409999 is a modest number, since divided by 9999 gives 640 as remainder.

6409999 is a lucky number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6479999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31014 + ... + 31219.

It is an arithmetic number, because the mean of its divisors is an integer number (1618084).

Almost surely, 2^6409999 is an apocalyptic number.

6409999 is a deficient number, since it is larger than the sum of its proper divisors (62337).

6409999 is a wasteful number, since it uses less digits than its factorization.

6409999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62336.

The product of its (nonzero) digits is 157464, while the sum is 46.

The square root of 6409999 is about 2531.7975827463. The cubic root of 6409999 is about 185.7601931312.

The spelling of 6409999 in words is "six million, four hundred nine thousand, nine hundred ninety-nine".