1685738731 has 2 divisors, whose sum is σ = 1685738732. Its totient is φ = 1685738730.

The previous prime is 1685738647. The next prime is 1685738741. The reversal of 1685738731 is 1378375861.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1685738731 - 2⁷ = 1685738603 is a prime.

It is a super-2 number, since 2×1685738731² = 5683430138386980722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1685738741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 842869365 + 842869366.

It is an arithmetic number, because the mean of its divisors is an integer number (842869366).

Almost surely, 2^1685738731 is an apocalyptic number.

1685738731 is a deficient number, since it is larger than the sum of its proper divisors (1).

1685738731 is an equidigital number, since it uses as much as digits as its factorization.

1685738731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 846720, while the sum is 49.

The square root of 1685738731 is about 41057.7487327301. The cubic root of 1685738731 is about 1190.1364462333.

The spelling of 1685738731 in words is "one billion, six hundred eighty-five million, seven hundred thirty-eight thousand, seven hundred thirty-one".