85131691 has 2 divisors, whose sum is σ = 85131692. Its totient is φ = 85131690.

The previous prime is 85131659. The next prime is 85131713. The reversal of 85131691 is 19613158.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 85131691 - 2⁵ = 85131659 is a prime.

It is not a weakly prime, because it can be changed into another prime (85131391) 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, 42565845 + 42565846.

It is an arithmetic number, because the mean of its divisors is an integer number (42565846).

Almost surely, 2^85131691 is an apocalyptic number.

85131691 is a deficient number, since it is larger than the sum of its proper divisors (1).

85131691 is an equidigital number, since it uses as much as digits as its factorization.

85131691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6480, while the sum is 34.

The square root of 85131691 is about 9226.6836403986. The cubic root of 85131691 is about 439.9099178533.

The spelling of 85131691 in words is "eighty-five million, one hundred thirty-one thousand, six hundred ninety-one".