6403891 has 12 divisors (see below), whose sum is σ = 7077952. Its totient is φ = 5759568.

The previous prime is 6403889. The next prime is 6403907. The reversal of 6403891 is 1983046.

It is not a de Polignac number, because 6403891 - 2¹ = 6403889 is a prime.

It is a Duffinian number.

6403891 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6403811) 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 11 ways as a sum of consecutive naturals, for example, 28606 + ... + 28828.

Almost surely, 2^6403891 is an apocalyptic number.

6403891 is a deficient number, since it is larger than the sum of its proper divisors (674061).

6403891 is a wasteful number, since it uses less digits than its factorization.

6403891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330 (or 283 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 6403891 is about 2530.5910376827. The cubic root of 6403891 is about 185.7011716014.

The spelling of 6403891 in words is "six million, four hundred three thousand, eight hundred ninety-one".