8749543221 has 12 divisors (see below), whose sum is σ = 13381654572. Its totient is φ = 5489909376.

The previous prime is 8749543151. The next prime is 8749543247. The reversal of 8749543221 is 1223459478.

8749543221 is a `hidden beast` number, since 87 + 4 + 9 + 543 + 2 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 7799362596 + 950180625 = 88314^2 + 30825^2 .

It is not a de Polignac number, because 8749543221 - 2⁹ = 8749542709 is a prime.

It is a super-2 number, since 2×8749543221² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8749543921) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28593126 + ... + 28593431.

It is an arithmetic number, because the mean of its divisors is an integer number (1115137881).

Almost surely, 2^8749543221 is an apocalyptic number.

It is an amenable number.

8749543221 is a deficient number, since it is larger than the sum of its proper divisors (4632111351).

8749543221 is a wasteful number, since it uses less digits than its factorization.

8749543221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57186580 (or 57186577 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 8749543221 is about 93538.9930510266. The cubic root of 8749543221 is about 2060.6067918217.

It can be divided in two parts, 8749543 and 221, that added together give a square (8749764 = 2958²).

The spelling of 8749543221 in words is "eight billion, seven hundred forty-nine million, five hundred forty-three thousand, two hundred twenty-one".