8721257549 has 4 divisors (see below), whose sum is σ = 8924077536. Its totient is φ = 8518437564.

The previous prime is 8721257459. The next prime is 8721257557. The reversal of 8721257549 is 9457521278.

8721257549 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 8721257549 - 2¹⁶ = 8721192013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 8721257497 and 8721257506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8721257449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101409929 + ... + 101410014.

It is an arithmetic number, because the mean of its divisors is an integer number (2231019384).

Almost surely, 2^8721257549 is an apocalyptic number.

It is an amenable number.

8721257549 is a deficient number, since it is larger than the sum of its proper divisors (202819987).

8721257549 is a wasteful number, since it uses less digits than its factorization.

8721257549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202819986.

The product of its digits is 1411200, while the sum is 50.

The square root of 8721257549 is about 93387.6734317758. The cubic root of 8721257549 is about 2058.3838731178.

The spelling of 8721257549 in words is "eight billion, seven hundred twenty-one million, two hundred fifty-seven thousand, five hundred forty-nine".