6666655129 has 4 divisors (see below), whose sum is σ = 6693215760. Its totient is φ = 6640094500.

The previous prime is 6666655117. The next prime is 6666655147. The reversal of 6666655129 is 9215566666.

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, and also an emirpimes, since its reverse is a distinct semiprime: 9215566666 = 2 ⋅4607783333.

It is a cyclic number.

It is not a de Polignac number, because 6666655129 - 2⁵ = 6666655097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6666655109) 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, 13279939 + ... + 13280440.

It is an arithmetic number, because the mean of its divisors is an integer number (1673303940).

Almost surely, 2^6666655129 is an apocalyptic number.

It is an amenable number.

6666655129 is a deficient number, since it is larger than the sum of its proper divisors (26560631).

6666655129 is a wasteful number, since it uses less digits than its factorization.

6666655129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26560630.

The product of its digits is 3499200, while the sum is 52.

The square root of 6666655129 is about 81649.5874392516. The cubic root of 6666655129 is about 1882.0709720254.

The spelling of 6666655129 in words is "six billion, six hundred sixty-six million, six hundred fifty-five thousand, one hundred twenty-nine".