6404015 has 4 divisors (see below), whose sum is σ = 7684824. Its totient is φ = 5123208.

The previous prime is 6404009. The next prime is 6404017. The reversal of 6404015 is 5104046.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 6404015 - 2²⁰ = 5355439 is a prime.

It is a super-2 number, since 2×6404015² = 82022816240450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6404017) 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, 640397 + ... + 640406.

It is an arithmetic number, because the mean of its divisors is an integer number (1921206).

Almost surely, 2^6404015 is an apocalyptic number.

6404015 is a deficient number, since it is larger than the sum of its proper divisors (1280809).

6404015 is a wasteful number, since it uses less digits than its factorization.

6404015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1280808.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 6404015 is about 2530.6155377694. The cubic root of 6404015 is about 185.7023701851.

The spelling of 6404015 in words is "six million, four hundred four thousand, fifteen".