1687465861 has 2 divisors, whose sum is σ = 1687465862. Its totient is φ = 1687465860.

The previous prime is 1687465859. The next prime is 1687465907. The reversal of 1687465861 is 1685647861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 908721025 + 778744836 = 30145^2 + 27906^2 .

It is a cyclic number.

It is not a de Polignac number, because 1687465861 - 2¹ = 1687465859 is a prime.

Together with 1687465859, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 1687465799 and 1687465808.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1687465831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 843732930 + 843732931.

It is an arithmetic number, because the mean of its divisors is an integer number (843732931).

Almost surely, 2^1687465861 is an apocalyptic number.

It is an amenable number.

1687465861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1687465861 is an equidigital number, since it uses as much as digits as its factorization.

1687465861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1935360, while the sum is 52.

The square root of 1687465861 is about 41078.7762841105. The cubic root of 1687465861 is about 1190.5427604354.

The spelling of 1687465861 in words is "one billion, six hundred eighty-seven million, four hundred sixty-five thousand, eight hundred sixty-one".