8939228721 has 4 divisors (see below), whose sum is σ = 11918971632. Its totient is φ = 5959485812.

The previous prime is 8939228719. The next prime is 8939228731. The reversal of 8939228721 is 1278229398.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 8939228721 - 2¹ = 8939228719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8939228731) 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, 1489871451 + ... + 1489871456.

It is an arithmetic number, because the mean of its divisors is an integer number (2979742908).

Almost surely, 2^8939228721 is an apocalyptic number.

It is an amenable number.

8939228721 is a deficient number, since it is larger than the sum of its proper divisors (2979742911).

8939228721 is a wasteful number, since it uses less digits than its factorization.

8939228721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2979742910.

The product of its digits is 870912, while the sum is 51.

The square root of 8939228721 is about 94547.4945252385. The cubic root of 8939228721 is about 2075.3914176008.

The spelling of 8939228721 in words is "eight billion, nine hundred thirty-nine million, two hundred twenty-eight thousand, seven hundred twenty-one".