6665530666 has 4 divisors (see below), whose sum is σ = 9998296002. Its totient is φ = 3332765332.

The previous prime is 6665530643. The next prime is 6665530681. The reversal of 6665530666 is 6660355666.

6665530666 is nontrivially palindromic in base 14.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6660355666 = 2 ⋅3330177833.

It can be written as a sum of positive squares in only one way, i.e., 5988438225 + 677092441 = 77385^2 + 26021^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1666382665 + ... + 1666382668.

Almost surely, 2^6665530666 is an apocalyptic number.

6665530666 is a deficient number, since it is larger than the sum of its proper divisors (3332765336).

6665530666 is a wasteful number, since it uses less digits than its factorization.

6665530666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3332765335.

The product of its (nonzero) digits is 3499200, while the sum is 49.

The square root of 6665530666 is about 81642.7012414459. The cubic root of 6665530666 is about 1881.9651499338.

The spelling of 6665530666 in words is "six billion, six hundred sixty-five million, five hundred thirty thousand, six hundred sixty-six".