400504109 has 2 divisors, whose sum is σ = 400504110. Its totient is φ = 400504108.

The previous prime is 400504033. The next prime is 400504121. The reversal of 400504109 is 901405004.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 399880009 + 624100 = 19997^2 + 790^2 .

It is a cyclic number.

It is not a de Polignac number, because 400504109 - 2²⁰ = 399455533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400504189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200252054 + 200252055.

It is an arithmetic number, because the mean of its divisors is an integer number (200252055).

Almost surely, 2^400504109 is an apocalyptic number.

It is an amenable number.

400504109 is a deficient number, since it is larger than the sum of its proper divisors (1).

400504109 is an equidigital number, since it uses as much as digits as its factorization.

400504109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 400504109 is about 20012.5987567832. The cubic root of 400504109 is about 737.1156953626.

The spelling of 400504109 in words is "four hundred million, five hundred four thousand, one hundred nine".