6400813 has 2 divisors, whose sum is σ = 6400814. Its totient is φ = 6400812.

The previous prime is 6400799. The next prime is 6400837. The reversal of 6400813 is 3180046.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5484964 + 915849 = 2342^2 + 957^2 .

It is a cyclic number.

It is not a de Polignac number, because 6400813 - 2²¹ = 4303661 is a prime.

6400813 is a modest number, since divided by 813 gives 64 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6400843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3200406 + 3200407.

It is an arithmetic number, because the mean of its divisors is an integer number (3200407).

Almost surely, 2^6400813 is an apocalyptic number.

It is an amenable number.

6400813 is a deficient number, since it is larger than the sum of its proper divisors (1).

6400813 is an equidigital number, since it uses as much as digits as its factorization.

6400813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 6400813 is about 2529.9828062657. The cubic root of 6400813 is about 185.6714147027.

Adding to 6400813 its reverse (3180046), we get a palindrome (9580859).

The spelling of 6400813 in words is "six million, four hundred thousand, eight hundred thirteen".