655381 has 4 divisors (see below), whose sum is σ = 673132. Its totient is φ = 637632.

The previous prime is 655379. The next prime is 655387. The reversal of 655381 is 183556.

It is the 331-st star number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 600625 + 54756 = 775^2 + 234^2 .

It is a cyclic number.

It is not a de Polignac number, because 655381 - 2¹ = 655379 is a prime.

It is a super-2 number, since 2×655381² = 859048510322, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (655387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8820 + ... + 8893.

It is an arithmetic number, because the mean of its divisors is an integer number (168283).

2⁶⁵⁵³⁸¹ is an apocalyptic number.

It is an amenable number.

655381 is a deficient number, since it is larger than the sum of its proper divisors (17751).

655381 is a wasteful number, since it uses less digits than its factorization.

655381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17750.

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

The square root of 655381 is about 809.5560511787. The cubic root of 655381 is about 86.8622915006.

The spelling of 655381 in words is "six hundred fifty-five thousand, three hundred eighty-one".