400005173 has 2 divisors, whose sum is σ = 400005174. Its totient is φ = 400005172.

The previous prime is 400005163. The next prime is 400005211. The reversal of 400005173 is 371500004.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 259274404 + 140730769 = 16102^2 + 11863^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400005173 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400005103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200002586 + 200002587.

It is an arithmetic number, because the mean of its divisors is an integer number (200002587).

Almost surely, 2^400005173 is an apocalyptic number.

It is an amenable number.

400005173 is a deficient number, since it is larger than the sum of its proper divisors (1).

400005173 is an equidigital number, since it uses as much as digits as its factorization.

400005173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 400005173 is about 20000.1293245819. The cubic root of 400005173 is about 736.8094759635.

Adding to 400005173 its reverse (371500004), we get a palindrome (771505177).

The spelling of 400005173 in words is "four hundred million, five thousand, one hundred seventy-three".