1681181 has 4 divisors (see below), whose sum is σ = 1780092. Its totient is φ = 1582272.

The previous prime is 1681157. The next prime is 1681187. The reversal of 1681181 is 1811861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1811861 = 131 ⋅13831.

It can be written as a sum of positive squares in 2 ways, for example, as 931225 + 749956 = 965^2 + 866^2 .

It is a cyclic number.

It is not a de Polignac number, because 1681181 - 2¹⁴ = 1664797 is a prime.

It is a super-2 number, since 2×1681181² = 5652739109522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1681181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681187) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49430 + ... + 49463.

It is an arithmetic number, because the mean of its divisors is an integer number (445023).

2^1681181 is an apocalyptic number.

It is an amenable number.

1681181 is a deficient number, since it is larger than the sum of its proper divisors (98911).

1681181 is an equidigital number, since it uses as much as digits as its factorization.

1681181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98910.

The product of its digits is 384, while the sum is 26.

The square root of 1681181 is about 1296.6036402849. The cubic root of 1681181 is about 118.9062887678.

The spelling of 1681181 in words is "one million, six hundred eighty-one thousand, one hundred eighty-one".