6666260138 has 4 divisors (see below), whose sum is σ = 9999390210. Its totient is φ = 3333130068.

The previous prime is 6666260123. The next prime is 6666260171. The reversal of 6666260138 is 8310626666.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 6356394529 + 309865609 = 79727^2 + 17603^2 .

It is a Curzon number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 1666565033 + ... + 1666565036.

Almost surely, 2^6666260138 is an apocalyptic number.

6666260138 is a deficient number, since it is larger than the sum of its proper divisors (3333130072).

6666260138 is a wasteful number, since it uses less digits than its factorization.

6666260138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3333130071.

The product of its (nonzero) digits is 373248, while the sum is 44.

The square root of 6666260138 is about 81647.1685853221. The cubic root of 6666260138 is about 1882.0338011722.

The spelling of 6666260138 in words is "six billion, six hundred sixty-six million, two hundred sixty thousand, one hundred thirty-eight".