85221731 has 24 divisors (see below), whose sum is σ = 105636960. Its totient is φ = 68312832.

The previous prime is 85221727. The next prime is 85221751. The reversal of 85221731 is 13712258.

It is not a de Polignac number, because 85221731 - 2² = 85221727 is a prime.

It is a super-2 number, since 2×85221731² = 14525486869272722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 85221694 and 85221703.

It is not an unprimeable number, because it can be changed into a prime (85221751) 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 in 23 ways as a sum of consecutive naturals, for example, 218885 + ... + 219273.

It is an arithmetic number, because the mean of its divisors is an integer number (4401540).

Almost surely, 2^85221731 is an apocalyptic number.

85221731 is a deficient number, since it is larger than the sum of its proper divisors (20415229).

85221731 is a wasteful number, since it uses less digits than its factorization.

85221731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 683 (or 676 counting only the distinct ones).

The product of its digits is 3360, while the sum is 29.

The square root of 85221731 is about 9231.5616772028. The cubic root of 85221731 is about 440.0649542537.

Adding to 85221731 its reverse (13712258), we get a palindrome (98933989).

The spelling of 85221731 in words is "eighty-five million, two hundred twenty-one thousand, seven hundred thirty-one".