6403816 has 8 divisors (see below), whose sum is σ = 12007170. Its totient is φ = 3201904.

The previous prime is 6403811. The next prime is 6403847. The reversal of 6403816 is 6183046.

It can be written as a sum of positive squares in only one way, i.e., 6400900 + 2916 = 2530^2 + 54^2 .

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

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (6403811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 400231 + ... + 400246.

Almost surely, 2^6403816 is an apocalyptic number.

It is an amenable number.

6403816 is a deficient number, since it is larger than the sum of its proper divisors (5603354).

6403816 is a wasteful number, since it uses less digits than its factorization.

6403816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 800483 (or 800479 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 6403816 is about 2530.5762189667. The cubic root of 6403816 is about 185.7004466442.

The spelling of 6403816 in words is "six million, four hundred three thousand, eight hundred sixteen".