1985910697 has 2 divisors, whose sum is σ = 1985910698. Its totient is φ = 1985910696.

The previous prime is 1985910679. The next prime is 1985910733. The reversal of 1985910697 is 7960195891.

Together with previous prime (1985910679) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1870649001 + 115261696 = 43251^2 + 10736^2 .

It is a cyclic number.

It is not a de Polignac number, because 1985910697 - 2¹¹ = 1985908649 is a prime.

It is not a weakly prime, because it can be changed into another prime (1985910497) 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, 992955348 + 992955349.

It is an arithmetic number, because the mean of its divisors is an integer number (992955349).

Almost surely, 2^1985910697 is an apocalyptic number.

It is an amenable number.

1985910697 is a deficient number, since it is larger than the sum of its proper divisors (1).

1985910697 is an equidigital number, since it uses as much as digits as its factorization.

1985910697 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1224720, while the sum is 55.

The square root of 1985910697 is about 44563.5579481711. The cubic root of 1985910697 is about 1256.9555069779.

The spelling of 1985910697 in words is "one billion, nine hundred eighty-five million, nine hundred ten thousand, six hundred ninety-seven".