6656438569 has 9 divisors (see below), whose sum is σ = 7317567831. Its totient is φ = 6050491920.

The previous prime is 6656438531. The next prime is 6656438597. The reversal of 6656438569 is 9658346566.

The square root of 6656438569 is 81587.

It is a perfect power (a square), and thus also a powerful number.

6656438569 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 5423586025 + 1232852544 = 73645^2 + 35112^2 .

It is not a de Polignac number, because 6656438569 - 2⁹ = 6656438057 is a prime.

It is a super-2 number, since 2×6656438569² = 88616348845741535522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6656438869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 893749 + ... + 901165.

Almost surely, 2^6656438569 is an apocalyptic number.

6656438569 is the 81587-th square number.

6656438569 is the 40794-th centered octagonal number.

It is an amenable number.

6656438569 is a deficient number, since it is larger than the sum of its proper divisors (661129262).

6656438569 is an frugal number, since it uses more digits than its factorization.

6656438569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14856 (or 7428 counting only the distinct ones).

The product of its digits is 27993600, while the sum is 58.

The cubic root of 6656438569 is about 1881.1090642733.

The spelling of 6656438569 in words is "six billion, six hundred fifty-six million, four hundred thirty-eight thousand, five hundred sixty-nine".