400004123 has 2 divisors, whose sum is σ = 400004124. Its totient is φ = 400004122.

The previous prime is 400004107. The next prime is 400004161. The reversal of 400004123 is 321400004.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 400004123 - 2⁴ = 400004107 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 400004098 and 400004107.

It is not a weakly prime, because it can be changed into another prime (400004173) 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, 200002061 + 200002062.

It is an arithmetic number, because the mean of its divisors is an integer number (200002062).

Almost surely, 2^400004123 is an apocalyptic number.

400004123 is a deficient number, since it is larger than the sum of its proper divisors (1).

400004123 is an equidigital number, since it uses as much as digits as its factorization.

400004123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 400004123 is about 20000.1030747344. The cubic root of 400004123 is about 736.8088312630.

Adding to 400004123 its reverse (321400004), we get a palindrome (721404127).

The spelling of 400004123 in words is "four hundred million, four thousand, one hundred twenty-three".