9867528221 has 4 divisors (see below), whose sum is σ = 9871278492. Its totient is φ = 9863777952.

The previous prime is 9867528217. The next prime is 9867528227. The reversal of 9867528221 is 1228257689.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2128807321 + 7738720900 = 46139^2 + 87970^2 .

It is a cyclic number.

It is not a de Polignac number, because 9867528221 - 2² = 9867528217 is a prime.

It is a super-2 number, since 2×9867528221² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 9867528221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9867528227) 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 3 ways as a sum of consecutive naturals, for example, 1871186 + ... + 1876451.

It is an arithmetic number, because the mean of its divisors is an integer number (2467819623).

Almost surely, 2^9867528221 is an apocalyptic number.

It is an amenable number.

9867528221 is a deficient number, since it is larger than the sum of its proper divisors (3750271).

9867528221 is a wasteful number, since it uses less digits than its factorization.

9867528221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3750270.

The product of its digits is 967680, while the sum is 50.

The square root of 9867528221 is about 99335.4328575660. The cubic root of 9867528221 is about 2144.8789763694.

The spelling of 9867528221 in words is "nine billion, eight hundred sixty-seven million, five hundred twenty-eight thousand, two hundred twenty-one".