400444111993 has 2 divisors, whose sum is σ = 400444111994. Its totient is φ = 400444111992.

The previous prime is 400444111973. The next prime is 400444112009. The reversal of 400444111993 is 399111444004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 223301612304 + 177142499689 = 472548^2 + 420883^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400444111993 is a prime.

It is not a weakly prime, because it can be changed into another prime (400444111973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200222055996 + 200222055997.

It is an arithmetic number, because the mean of its divisors is an integer number (200222055997).

Almost surely, 2^400444111993 is an apocalyptic number.

It is an amenable number.

400444111993 is a deficient number, since it is larger than the sum of its proper divisors (1).

400444111993 is an equidigital number, since it uses as much as digits as its factorization.

400444111993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 40.

Adding to 400444111993 its reverse (399111444004), we get a palindrome (799555555997).

The spelling of 400444111993 in words is "four hundred billion, four hundred forty-four million, one hundred eleven thousand, nine hundred ninety-three".