8551211721 has 16 divisors (see below), whose sum is σ = 12281283840. Its totient is φ = 5261160960.

The previous prime is 8551211717. The next prime is 8551211741. The reversal of 8551211721 is 1271121558.

8551211721 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 8551211721 - 2² = 8551211717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8551211741) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 185200 + ... + 226718.

It is an arithmetic number, because the mean of its divisors is an integer number (767580240).

Almost surely, 2^8551211721 is an apocalyptic number.

It is an amenable number.

8551211721 is a deficient number, since it is larger than the sum of its proper divisors (3730072119).

8551211721 is a wasteful number, since it uses less digits than its factorization.

8551211721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46816.

The product of its digits is 5600, while the sum is 33.

The square root of 8551211721 is about 92472.7620491569. The cubic root of 8551211721 is about 2044.9179468236.

The spelling of 8551211721 in words is "eight billion, five hundred fifty-one million, two hundred eleven thousand, seven hundred twenty-one".