565381 has 2 divisors, whose sum is σ = 565382. Its totient is φ = 565380.

The previous prime is 565379. The next prime is 565387. The reversal of 565381 is 183565.

565381 is nontrivially palindromic in base 9.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 320356 + 245025 = 566^2 + 495^2 .

It is a cyclic number.

It is not a de Polignac number, because 565381 - 2¹ = 565379 is a prime.

It is a super-2 number, since 2×565381² = 639311350322, which contains 22 as substring.

Together with 565379, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (565387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 282690 + 282691.

It is an arithmetic number, because the mean of its divisors is an integer number (282691).

2⁵⁶⁵³⁸¹ is an apocalyptic number.

It is an amenable number.

565381 is a deficient number, since it is larger than the sum of its proper divisors (1).

565381 is an equidigital number, since it uses as much as digits as its factorization.

565381 is an evil number, because the sum of its binary digits is even.

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

The square root of 565381 is about 751.9182136376. The cubic root of 565381 is about 82.6888724454.

It can be divided in two parts, 565 and 381, that added together give a triangular number (946 = T₄₃).

The spelling of 565381 in words is "five hundred sixty-five thousand, three hundred eighty-one".