6405993 has 16 divisors (see below), whose sum is σ = 10353600. Its totient is φ = 3882240.

The previous prime is 6405989. The next prime is 6406051. The reversal of 6405993 is 3995046.

6405993 is a `hidden beast` number, since 64 + 0 + 599 + 3 = 666.

It is not a de Polignac number, because 6405993 - 2² = 6405989 is a prime.

It is an Ulam number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6405913) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10488 + ... + 11081.

It is an arithmetic number, because the mean of its divisors is an integer number (647100).

Almost surely, 2^6405993 is an apocalyptic number.

It is an amenable number.

6405993 is a deficient number, since it is larger than the sum of its proper divisors (3947607).

6405993 is a wasteful number, since it uses less digits than its factorization.

6405993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21589 (or 21583 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 36.

The square root of 6405993 is about 2531.0063216041. The cubic root of 6405993 is about 185.7214874356.

The spelling of 6405993 in words is "six million, four hundred five thousand, nine hundred ninety-three".