6403864 has 8 divisors (see below), whose sum is σ = 12007260. Its totient is φ = 3201928.

The previous prime is 6403853. The next prime is 6403877. The reversal of 6403864 is 4683046.

It is a tau number, because it is divible by the number of its divisors (8).

It is a zygodrome in base 3.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 400234 + ... + 400249.

Almost surely, 2^6403864 is an apocalyptic number.

It is an amenable number.

6403864 is a deficient number, since it is larger than the sum of its proper divisors (5603396).

6403864 is a wasteful number, since it uses less digits than its factorization.

6403864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 800489 (or 800485 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 31.

The square root of 6403864 is about 2530.5857029550. The cubic root of 6403864 is about 185.7009106175.

The spelling of 6403864 in words is "six million, four hundred three thousand, eight hundred sixty-four".