400344409 has 2 divisors, whose sum is σ = 400344410. Its totient is φ = 400344408.

The previous prime is 400344401. The next prime is 400344431. The reversal of 400344409 is 904443004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 338376025 + 61968384 = 18395^2 + 7872^2 .

It is a cyclic number.

It is not a de Polignac number, because 400344409 - 2³ = 400344401 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (400344401) 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, 200172204 + 200172205.

It is an arithmetic number, because the mean of its divisors is an integer number (200172205).

Almost surely, 2^400344409 is an apocalyptic number.

It is an amenable number.

400344409 is a deficient number, since it is larger than the sum of its proper divisors (1).

400344409 is an equidigital number, since it uses as much as digits as its factorization.

400344409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 400344409 is about 20008.6083723981. The cubic root of 400344409 is about 737.0177079980.

The spelling of 400344409 in words is "four hundred million, three hundred forty-four thousand, four hundred nine".