85131531 has 6 divisors (see below), whose sum is σ = 122967780. Its totient is φ = 56754348.

The previous prime is 85131521. The next prime is 85131569. The reversal of 85131531 is 13513158.

It is not a de Polignac number, because 85131531 - 2⁵ = 85131499 is a prime.

It is a super-2 number, since 2×85131531² = 14494755140807922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 85131495 and 85131504.

It is not an unprimeable number, because it can be changed into a prime (85131511) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4729521 + ... + 4729538.

It is an arithmetic number, because the mean of its divisors is an integer number (20494630).

Almost surely, 2^85131531 is an apocalyptic number.

85131531 is a deficient number, since it is larger than the sum of its proper divisors (37836249).

85131531 is a wasteful number, since it uses less digits than its factorization.

85131531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9459065 (or 9459062 counting only the distinct ones).

The product of its digits is 1800, while the sum is 27.

The square root of 85131531 is about 9226.6749698903. The cubic root of 85131531 is about 439.9096422582.

Adding to 85131531 its reverse (13513158), we get a palindrome (98644689).

The spelling of 85131531 in words is "eighty-five million, one hundred thirty-one thousand, five hundred thirty-one".