399942400009 has 2 divisors, whose sum is σ = 399942400010. Its totient is φ = 399942400008.

The previous prime is 399942399919. The next prime is 399942400037. The reversal of 399942400009 is 900004249993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 379791177984 + 20151222025 = 616272^2 + 141955^2 .

It is a cyclic number.

It is not a de Polignac number, because 399942400009 - 2⁷ = 399942399881 is a prime.

It is not a weakly prime, because it can be changed into another prime (399942400409) 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, 199971200004 + 199971200005.

It is an arithmetic number, because the mean of its divisors is an integer number (199971200005).

Almost surely, 2^399942400009 is an apocalyptic number.

It is an amenable number.

399942400009 is a deficient number, since it is larger than the sum of its proper divisors (1).

399942400009 is an equidigital number, since it uses as much as digits as its factorization.

399942400009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 629856, while the sum is 49.

The spelling of 399942400009 in words is "three hundred ninety-nine billion, nine hundred forty-two million, four hundred thousand, nine".