400243973 has 2 divisors, whose sum is σ = 400243974. Its totient is φ = 400243972.

The previous prime is 400243951. The next prime is 400243981. The reversal of 400243973 is 379342004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 250842244 + 149401729 = 15838^2 + 12223^2 .

It is a cyclic number.

It is not a de Polignac number, because 400243973 - 2²⁰ = 399195397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400243913) 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, 200121986 + 200121987.

It is an arithmetic number, because the mean of its divisors is an integer number (200121987).

Almost surely, 2^400243973 is an apocalyptic number.

It is an amenable number.

400243973 is a deficient number, since it is larger than the sum of its proper divisors (1).

400243973 is an equidigital number, since it uses as much as digits as its factorization.

400243973 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 32.

The square root of 400243973 is about 20006.0983952394. The cubic root of 400243973 is about 736.9560699851.

Adding to 400243973 its reverse (379342004), we get a palindrome (779585977).

The spelling of 400243973 in words is "four hundred million, two hundred forty-three thousand, nine hundred seventy-three".