89561 has 2 divisors, whose sum is σ = 89562. Its totient is φ = 89560.

The previous prime is 89533. The next prime is 89563. The reversal of 89561 is 16598.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65536 + 24025 = 256^2 + 155^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-89561 is a prime.

Together with 89563, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (89563) 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, 44780 + 44781.

It is an arithmetic number, because the mean of its divisors is an integer number (44781).

2⁸⁹⁵⁶¹ is an apocalyptic number.

It is an amenable number.

89561 is a deficient number, since it is larger than the sum of its proper divisors (1).

89561 is an equidigital number, since it uses as much as digits as its factorization.

89561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 29.

The square root of 89561 is about 299.2674389238. The cubic root of 89561 is about 44.7410643499.

The spelling of 89561 in words is "eighty-nine thousand, five hundred sixty-one".