400043243 has 4 divisors (see below), whose sum is σ = 402692688. Its totient is φ = 397393800.

The previous prime is 400043227. The next prime is 400043257. The reversal of 400043243 is 342340004.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 400043243 - 2⁴ = 400043227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400043143) 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 in 3 ways as a sum of consecutive naturals, for example, 1324496 + ... + 1324797.

It is an arithmetic number, because the mean of its divisors is an integer number (100673172).

Almost surely, 2^400043243 is an apocalyptic number.

400043243 is a deficient number, since it is larger than the sum of its proper divisors (2649445).

400043243 is a wasteful number, since it uses less digits than its factorization.

400043243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2649444.

The product of its (nonzero) digits is 1152, while the sum is 20.

The square root of 400043243 is about 20001.0810457835. The cubic root of 400043243 is about 736.8328502003.

Adding to 400043243 its reverse (342340004), we get a palindrome (742383247).

The spelling of 400043243 in words is "four hundred million, forty-three thousand, two hundred forty-three".