85631239 has 2 divisors, whose sum is σ = 85631240. Its totient is φ = 85631238.

The previous prime is 85631237. The next prime is 85631257. The reversal of 85631239 is 93213658.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 85631239 - 2¹ = 85631237 is a prime.

Together with 85631237, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 85631198 and 85631207.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85631237) 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, 42815619 + 42815620.

It is an arithmetic number, because the mean of its divisors is an integer number (42815620).

Almost surely, 2^85631239 is an apocalyptic number.

85631239 is a deficient number, since it is larger than the sum of its proper divisors (1).

85631239 is an equidigital number, since it uses as much as digits as its factorization.

85631239 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38880, while the sum is 37.

The square root of 85631239 is about 9253.7148756594. The cubic root of 85631239 is about 440.7686958791.

The spelling of 85631239 in words is "eighty-five million, six hundred thirty-one thousand, two hundred thirty-nine".