85566921 has 16 divisors (see below), whose sum is σ = 124616448. Its totient is φ = 51794000.

The previous prime is 85566917. The next prime is 85566953. The reversal of 85566921 is 12966558.

It is a cyclic number.

It is not a de Polignac number, because 85566921 - 2² = 85566917 is a prime.

It is not an unprimeable number, because it can be changed into a prime (85566911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46990 + ... + 48776.

It is an arithmetic number, because the mean of its divisors is an integer number (7788528).

Almost surely, 2^85566921 is an apocalyptic number.

It is an amenable number.

85566921 is a deficient number, since it is larger than the sum of its proper divisors (39049527).

85566921 is a wasteful number, since it uses less digits than its factorization.

85566921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3252.

The product of its digits is 129600, while the sum is 42.

The square root of 85566921 is about 9250.2389698861. The cubic root of 85566921 is about 440.6583138033.

It can be divided in two parts, 855 and 66921, that added together give a palindrome (67776).

The spelling of 85566921 in words is "eighty-five million, five hundred sixty-six thousand, nine hundred twenty-one".