6396405 has 8 divisors (see below), whose sum is σ = 10234272. Its totient is φ = 3411408.

The previous prime is 6396389. The next prime is 6396409. The reversal of 6396405 is 5046936.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6396405 - 2⁴ = 6396389 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6396409) 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 7 ways as a sum of consecutive naturals, for example, 213199 + ... + 213228.

It is an arithmetic number, because the mean of its divisors is an integer number (1279284).

Almost surely, 2^6396405 is an apocalyptic number.

It is an amenable number.

6396405 is a deficient number, since it is larger than the sum of its proper divisors (3837867).

6396405 is a wasteful number, since it uses less digits than its factorization.

6396405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426435.

The product of its (nonzero) digits is 19440, while the sum is 33.

The square root of 6396405 is about 2529.1115040662. Note that the first 3 decimals coincide. The cubic root of 6396405 is about 185.6287832670.

The spelling of 6396405 in words is "six million, three hundred ninety-six thousand, four hundred five".