400006813 has 2 divisors, whose sum is σ = 400006814. Its totient is φ = 400006812.

The previous prime is 400006811. The next prime is 400006819. The reversal of 400006813 is 318600004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 372412804 + 27594009 = 19298^2 + 5253^2 .

It is a cyclic number.

It is not a de Polignac number, because 400006813 - 2¹ = 400006811 is a prime.

Together with 400006811, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400006811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200003406 + 200003407.

It is an arithmetic number, because the mean of its divisors is an integer number (200003407).

Almost surely, 2^400006813 is an apocalyptic number.

It is an amenable number.

400006813 is a deficient number, since it is larger than the sum of its proper divisors (1).

400006813 is an equidigital number, since it uses as much as digits as its factorization.

400006813 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 400006813 is about 20000.1703242747. The cubic root of 400006813 is about 736.8104829221.

Adding to 400006813 its reverse (318600004), we get a palindrome (718606817).

The spelling of 400006813 in words is "four hundred million, six thousand, eight hundred thirteen".