8688939221 has 4 divisors (see below), whose sum is σ = 8778516012. Its totient is φ = 8599362432.

The previous prime is 8688939187. The next prime is 8688939223. The reversal of 8688939221 is 1229398868.

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 6563268196 + 2125671025 = 81014^2 + 46105^2 .

It is a cyclic number.

It is not a de Polignac number, because 8688939221 - 2¹⁰ = 8688938197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8688939223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44788250 + ... + 44788443.

It is an arithmetic number, because the mean of its divisors is an integer number (2194629003).

Almost surely, 2^8688939221 is an apocalyptic number.

It is an amenable number.

8688939221 is a deficient number, since it is larger than the sum of its proper divisors (89576791).

8688939221 is an equidigital number, since it uses as much as digits as its factorization.

8688939221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89576790.

The product of its digits is 2985984, while the sum is 56.

The square root of 8688939221 is about 93214.4796745656. The cubic root of 8688939221 is about 2055.8381444253.

The spelling of 8688939221 in words is "eight billion, six hundred eighty-eight million, nine hundred thirty-nine thousand, two hundred twenty-one".