400000043 has 2 divisors, whose sum is σ = 400000044. Its totient is φ = 400000042.

The previous prime is 400000009. The next prime is 400000049. The reversal of 400000043 is 340000004.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 400000043 - 2²⁶ = 332891179 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (400000049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200000021 + 200000022.

It is an arithmetic number, because the mean of its divisors is an integer number (200000022).

Almost surely, 2^400000043 is an apocalyptic number.

400000043 is a deficient number, since it is larger than the sum of its proper divisors (1).

400000043 is an equidigital number, since it uses as much as digits as its factorization.

400000043 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 11.

The square root of 400000043 is about 20000.0010750000. The cubic root of 400000043 is about 736.8063261303.

Adding to 400000043 its reverse (340000004), we get a palindrome (740000047).

The spelling of 400000043 in words is "four hundred million, forty-three", and thus it is an aban number.