6678105145209 has 27 divisors (see below), whose sum is σ = 9690350490093. Its totient is φ = 4431763429632.

The previous prime is 6678105145093. The next prime is 6678105145267. The reversal of 6678105145209 is 9025415018766.

It is a happy number.

The square root of 6678105145209 is 2584203.

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

6678105145209 is a `hidden beast` number, since 6 + 6 + 7 + 8 + 105 + 1 + 4 + 520 + 9 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 3435080439609 + 3243024705600 = 1853397^2 + 1800840^2 .

It is not a de Polignac number, because 6678105145209 - 2¹³ = 6678105137017 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6678105145279) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1806356049 + ... + 1806359745.

Almost surely, 2^{6678105145209} is an apocalyptic number.

6678105145209 is the 2584203-rd square number.

6678105145209 is the 1292102-nd centered octagonal number.

It is an amenable number.

6678105145209 is a deficient number, since it is larger than the sum of its proper divisors (3012245344884).

6678105145209 is an frugal number, since it uses more digits than its factorization.

6678105145209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7866 (or 3933 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 54.

The spelling of 6678105145209 in words is "six trillion, six hundred seventy-eight billion, one hundred five million, one hundred forty-five thousand, two hundred nine".