400204243 has 2 divisors, whose sum is σ = 400204244. Its totient is φ = 400204242.

The previous prime is 400204237. The next prime is 400204261. The reversal of 400204243 is 342402004.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 400204243 - 2¹⁷ = 400073171 is a prime.

It is a super-2 number, since 2×400204243² = 320326872230406098, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 400204243.

It is not a weakly prime, because it can be changed into another prime (400204043) 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, 200102121 + 200102122.

It is an arithmetic number, because the mean of its divisors is an integer number (200102122).

Almost surely, 2^400204243 is an apocalyptic number.

400204243 is a deficient number, since it is larger than the sum of its proper divisors (1).

400204243 is an equidigital number, since it uses as much as digits as its factorization.

400204243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 19.

The square root of 400204243 is about 20005.1054233663. The cubic root of 400204243 is about 736.9316846639.

Adding to 400204243 its reverse (342402004), we get a palindrome (742606247).

The spelling of 400204243 in words is "four hundred million, two hundred four thousand, two hundred forty-three".