1686800491 has 2 divisors, whose sum is σ = 1686800492. Its totient is φ = 1686800490.

The previous prime is 1686800477. The next prime is 1686800497. The reversal of 1686800491 is 1940086861.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1686800491 - 2⁵ = 1686800459 is a prime.

It is not a weakly prime, because it can be changed into another prime (1686800497) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 843400245 + 843400246.

It is an arithmetic number, because the mean of its divisors is an integer number (843400246).

Almost surely, 2^1686800491 is an apocalyptic number.

1686800491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1686800491 is an equidigital number, since it uses as much as digits as its factorization.

1686800491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 82944, while the sum is 43.

The square root of 1686800491 is about 41070.6767779641. The cubic root of 1686800491 is about 1190.3862623410.

The spelling of 1686800491 in words is "one billion, six hundred eighty-six million, eight hundred thousand, four hundred ninety-one".