86561971 has 2 divisors, whose sum is σ = 86561972. Its totient is φ = 86561970.

The previous prime is 86561953. The next prime is 86561999. The reversal of 86561971 is 17916568.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 86561971 - 2⁵ = 86561939 is a prime.

It is not a weakly prime, because it can be changed into another prime (86561911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43280985 + 43280986.

It is an arithmetic number, because the mean of its divisors is an integer number (43280986).

Almost surely, 2^86561971 is an apocalyptic number.

86561971 is a deficient number, since it is larger than the sum of its proper divisors (1).

86561971 is an equidigital number, since it uses as much as digits as its factorization.

86561971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 43.

The square root of 86561971 is about 9303.8686039733. The cubic root of 86561971 is about 442.3598602901.

The spelling of 86561971 in words is "eighty-six million, five hundred sixty-one thousand, nine hundred seventy-one".