400243331 has 2 divisors, whose sum is σ = 400243332. Its totient is φ = 400243330.

The previous prime is 400243289. The next prime is 400243339. The reversal of 400243331 is 133342004.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400243331 is a prime.

It is a super-2 number, since 2×400243331² = 320389448019951122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (400243339) 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, 200121665 + 200121666.

It is an arithmetic number, because the mean of its divisors is an integer number (200121666).

Almost surely, 2^400243331 is an apocalyptic number.

400243331 is a deficient number, since it is larger than the sum of its proper divisors (1).

400243331 is an equidigital number, since it uses as much as digits as its factorization.

400243331 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 20.

The square root of 400243331 is about 20006.0823501254. The cubic root of 400243331 is about 736.9556759537.

Adding to 400243331 its reverse (133342004), we get a palindrome (533585335).

The spelling of 400243331 in words is "four hundred million, two hundred forty-three thousand, three hundred thirty-one".