1355681 has 2 divisors, whose sum is σ = 1355682. Its totient is φ = 1355680.

The previous prime is 1355677. The next prime is 1355693. The reversal of 1355681 is 1865531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1175056 + 180625 = 1084^2 + 425^2 .

It is a cyclic number.

It is not a de Polignac number, because 1355681 - 2² = 1355677 is a prime.

It is a super-2 number, since 2×1355681² = 3675741947522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1355281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 677840 + 677841.

It is an arithmetic number, because the mean of its divisors is an integer number (677841).

2^1355681 is an apocalyptic number.

It is an amenable number.

1355681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1355681 is an equidigital number, since it uses as much as digits as its factorization.

1355681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3600, while the sum is 29.

The square root of 1355681 is about 1164.3371504852. The cubic root of 1355681 is about 110.6757575071.

The spelling of 1355681 in words is "one million, three hundred fifty-five thousand, six hundred eighty-one".