1686776861 has 32 divisors (see below), whose sum is σ = 2148560640. Its totient is φ = 1286208000.

The previous prime is 1686776849. The next prime is 1686776863.

1686776861 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1686776861 - 2¹⁰ = 1686775837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1686776797 and 1686776806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1686776863) 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 in 31 ways as a sum of consecutive naturals, for example, 690935 + ... + 693371.

It is an arithmetic number, because the mean of its divisors is an integer number (67142520).

Almost surely, 2^1686776861 is an apocalyptic number.

1686776861 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1686776861 is a deficient number, since it is larger than the sum of its proper divisors (461783779).

1686776861 is a wasteful number, since it uses less digits than its factorization.

1686776861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2645.

The product of its digits is 4064256, while the sum is 56.

The square root of 1686776861 is about 41070.3891021256. The cubic root of 1686776861 is about 1190.3807036993.

The spelling of 1686776861 in words is "one billion, six hundred eighty-six million, seven hundred seventy-six thousand, eight hundred sixty-one".