355681 has 4 divisors (see below), whose sum is σ = 365332. Its totient is φ = 346032.

The previous prime is 355679. The next prime is 355697. The reversal of 355681 is 186553.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 186553 = 23 ⋅8111.

It can be written as a sum of positive squares in 2 ways, for example, as 342225 + 13456 = 585^2 + 116^2 .

It is a cyclic number.

It is not a de Polignac number, because 355681 - 2¹ = 355679 is a prime.

It is a super-2 number, since 2×355681² = 253017947522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (355651) 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, 4770 + ... + 4843.

It is an arithmetic number, because the mean of its divisors is an integer number (91333).

2³⁵⁵⁶⁸¹ is an apocalyptic number.

It is an amenable number.

355681 is a deficient number, since it is larger than the sum of its proper divisors (9651).

355681 is an equidigital number, since it uses as much as digits as its factorization.

355681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9650.

The product of its digits is 3600, while the sum is 28.

The square root of 355681 is about 596.3899730881. The cubic root of 355681 is about 70.8522351709.

The spelling of 355681 in words is "three hundred fifty-five thousand, six hundred eighty-one".