400440109 has 2 divisors, whose sum is σ = 400440110. Its totient is φ = 400440108.

The previous prime is 400440107. The next prime is 400440119. The reversal of 400440109 is 901044004.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 254562025 + 145878084 = 15955^2 + 12078^2 .

It is a cyclic number.

It is not a de Polignac number, because 400440109 - 2¹ = 400440107 is a prime.

Together with 400440107, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 400440109.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400440107) 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, 200220054 + 200220055.

It is an arithmetic number, because the mean of its divisors is an integer number (200220055).

Almost surely, 2^400440109 is an apocalyptic number.

It is an amenable number.

400440109 is a deficient number, since it is larger than the sum of its proper divisors (1).

400440109 is an equidigital number, since it uses as much as digits as its factorization.

400440109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 400440109 is about 20010.9997001649. Note that the first 3 decimals coincide. The cubic root of 400440109 is about 737.0764299165.

The spelling of 400440109 in words is "four hundred million, four hundred forty thousand, one hundred nine".