999780433997 has 2 divisors, whose sum is σ = 999780433998. Its totient is φ = 999780433996.

The previous prime is 999780433963. The next prime is 999780434021. The reversal of 999780433997 is 799334087999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 739082370601 + 260698063396 = 859699^2 + 510586^2 .

It is an emirp because it is prime and its reverse (799334087999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999780433997 - 2⁸ = 999780433741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999780433957) 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, 499890216998 + 499890216999.

It is an arithmetic number, because the mean of its divisors is an integer number (499890216999).

Almost surely, 2^999780433997 is an apocalyptic number.

It is an amenable number.

999780433997 is a deficient number, since it is larger than the sum of its proper divisors (1).

999780433997 is an equidigital number, since it uses as much as digits as its factorization.

999780433997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 833299488, while the sum is 77.

The spelling of 999780433997 in words is "nine hundred ninety-nine billion, seven hundred eighty million, four hundred thirty-three thousand, nine hundred ninety-seven".