1681365 has 32 divisors (see below), whose sum is σ = 3133440. Its totient is φ = 753984.

The previous prime is 1681363. The next prime is 1681397. The reversal of 1681365 is 5631861.

It is not a de Polignac number, because 1681365 - 2¹ = 1681363 is a prime.

It is a Curzon number.

1681365 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681363) 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, 6916 + ... + 7154.

It is an arithmetic number, because the mean of its divisors is an integer number (97920).

2^1681365 is an apocalyptic number.

1681365 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1681365 is a deficient number, since it is larger than the sum of its proper divisors (1452075).

1681365 is a wasteful number, since it uses less digits than its factorization.

1681365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321.

The product of its digits is 4320, while the sum is 30.

The square root of 1681365 is about 1296.6745929492. The cubic root of 1681365 is about 118.9106265833.

The spelling of 1681365 in words is "one million, six hundred eighty-one thousand, three hundred sixty-five".