6405813 has 6 divisors (see below), whose sum is σ = 9252854. Its totient is φ = 4270536.

The previous prime is 6405811. The next prime is 6405827. The reversal of 6405813 is 3185046.

6405813 is a `hidden beast` number, since 640 + 5 + 8 + 13 = 666.

It can be written as a sum of positive squares in only one way, i.e., 4028049 + 2377764 = 2007^2 + 1542^2 .

It is not a de Polignac number, because 6405813 - 2¹ = 6405811 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6405811) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 355870 + ... + 355887.

Almost surely, 2^6405813 is an apocalyptic number.

It is an amenable number.

6405813 is a deficient number, since it is larger than the sum of its proper divisors (2847041).

6405813 is a wasteful number, since it uses less digits than its factorization.

6405813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 711763 (or 711760 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 6405813 is about 2530.9707623756. The cubic root of 6405813 is about 185.7197479092.

The spelling of 6405813 in words is "six million, four hundred five thousand, eight hundred thirteen".