1711981 has 2 divisors, whose sum is σ = 1711982. Its totient is φ = 1711980.

The previous prime is 1711979. The next prime is 1711993. The reversal of 1711981 is 1891171.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1522756 + 189225 = 1234^2 + 435^2 .

It is an emirp because it is prime and its reverse (1891171) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1711981 - 2¹ = 1711979 is a prime.

It is a super-2 number, since 2×1711981² = 5861757888722, which contains 22 as substring.

Together with 1711979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1711901) 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, 855990 + 855991.

It is an arithmetic number, because the mean of its divisors is an integer number (855991).

2^1711981 is an apocalyptic number.

It is an amenable number.

1711981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1711981 is an equidigital number, since it uses as much as digits as its factorization.

1711981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 504, while the sum is 28.

The square root of 1711981 is about 1308.4269180967. The cubic root of 1711981 is about 119.6280380419.

The spelling of 1711981 in words is "one million, seven hundred eleven thousand, nine hundred eighty-one".