85916561 has 2 divisors, whose sum is σ = 85916562. Its totient is φ = 85916560.

The previous prime is 85916543. The next prime is 85916563. The reversal of 85916561 is 16561958.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49434961 + 36481600 = 7031^2 + 6040^2 .

It is a cyclic number.

It is not a de Polignac number, because 85916561 - 2¹⁰ = 85915537 is a prime.

Together with 85916563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (85916563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42958280 + 42958281.

It is an arithmetic number, because the mean of its divisors is an integer number (42958281).

Almost surely, 2^85916561 is an apocalyptic number.

It is an amenable number.

85916561 is a deficient number, since it is larger than the sum of its proper divisors (1).

85916561 is an equidigital number, since it uses as much as digits as its factorization.

85916561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64800, while the sum is 41.

The square root of 85916561 is about 9269.1186743940. The cubic root of 85916561 is about 441.2576980523.

The spelling of 85916561 in words is "eighty-five million, nine hundred sixteen thousand, five hundred sixty-one".