400108409 has 2 divisors, whose sum is σ = 400108410. Its totient is φ = 400108408.

The previous prime is 400108399. The next prime is 400108477. The reversal of 400108409 is 904801004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 301543225 + 98565184 = 17365^2 + 9928^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400108409 is a prime.

It is a super-2 number, since 2×400108409² = 320173477905022562, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (400108309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200054204 + 200054205.

It is an arithmetic number, because the mean of its divisors is an integer number (200054205).

Almost surely, 2^400108409 is an apocalyptic number.

It is an amenable number.

400108409 is a deficient number, since it is larger than the sum of its proper divisors (1).

400108409 is an equidigital number, since it uses as much as digits as its factorization.

400108409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 400108409 is about 20002.7100413919. The cubic root of 400108409 is about 736.8728574107.

The spelling of 400108409 in words is "four hundred million, one hundred eight thousand, four hundred nine".