85639691 has 2 divisors, whose sum is σ = 85639692. Its totient is φ = 85639690.

The previous prime is 85639667. The next prime is 85639717. The reversal of 85639691 is 19693658.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 85639691 - 2²² = 81445387 is a prime.

It is not a weakly prime, because it can be changed into another prime (85639991) 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, 42819845 + 42819846.

It is an arithmetic number, because the mean of its divisors is an integer number (42819846).

Almost surely, 2^85639691 is an apocalyptic number.

85639691 is a deficient number, since it is larger than the sum of its proper divisors (1).

85639691 is an equidigital number, since it uses as much as digits as its factorization.

85639691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 349920, while the sum is 47.

The square root of 85639691 is about 9254.1715458489. The cubic root of 85639691 is about 440.7831970296.

The spelling of 85639691 in words is "eighty-five million, six hundred thirty-nine thousand, six hundred ninety-one".