1990683757 has 2 divisors, whose sum is σ = 1990683758. Its totient is φ = 1990683756.

The previous prime is 1990683749. The next prime is 1990683797. The reversal of 1990683757 is 7573860991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1924927876 + 65755881 = 43874^2 + 8109^2 .

It is an emirp because it is prime and its reverse (7573860991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1990683757 - 2³ = 1990683749 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1990683698 and 1990683707.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1990683727) 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, 995341878 + 995341879.

It is an arithmetic number, because the mean of its divisors is an integer number (995341879).

Almost surely, 2^1990683757 is an apocalyptic number.

It is an amenable number.

1990683757 is a deficient number, since it is larger than the sum of its proper divisors (1).

1990683757 is an equidigital number, since it uses as much as digits as its factorization.

1990683757 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2857680, while the sum is 55.

The square root of 1990683757 is about 44617.0792074067. The cubic root of 1990683757 is about 1257.9617160230.

The spelling of 1990683757 in words is "one billion, nine hundred ninety million, six hundred eighty-three thousand, seven hundred fifty-seven".