400303021 has 2 divisors, whose sum is σ = 400303022. Its totient is φ = 400303020.

The previous prime is 400303009. The next prime is 400303051. The reversal of 400303021 is 120303004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 368256100 + 32046921 = 19190^2 + 5661^2 .

It is a cyclic number.

It is not a de Polignac number, because 400303021 - 2²¹ = 398205869 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 400302992 and 400303010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400303051) 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, 200151510 + 200151511.

It is an arithmetic number, because the mean of its divisors is an integer number (200151511).

Almost surely, 2^400303021 is an apocalyptic number.

It is an amenable number.

400303021 is a deficient number, since it is larger than the sum of its proper divisors (1).

400303021 is an equidigital number, since it uses as much as digits as its factorization.

400303021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 400303021 is about 20007.5740908287. The cubic root of 400303021 is about 736.9923092501.

Adding to 400303021 its reverse (120303004), we get a palindrome (520606025).

The spelling of 400303021 in words is "four hundred million, three hundred three thousand, twenty-one".