83561 has 2 divisors, whose sum is σ = 83562. Its totient is φ = 83560.

The previous prime is 83557. The next prime is 83563. The reversal of 83561 is 16538.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59536 + 24025 = 244^2 + 155^2 .

It is a cyclic number.

It is not a de Polignac number, because 83561 - 2² = 83557 is a prime.

Together with 83563, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 16.

It is not a weakly prime, because it can be changed into another prime (83563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41780 + 41781.

It is an arithmetic number, because the mean of its divisors is an integer number (41781).

2⁸³⁵⁶¹ is an apocalyptic number.

It is an amenable number.

83561 is a deficient number, since it is larger than the sum of its proper divisors (1).

83561 is an equidigital number, since it uses as much as digits as its factorization.

83561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 23.

The square root of 83561 is about 289.0691958684. The cubic root of 83561 is about 43.7187640986.

Subtracting from 83561 its sum of digits (23), we obtain a palindrome (83538).

The spelling of 83561 in words is "eighty-three thousand, five hundred sixty-one".