6667997666 has 32 divisors (see below), whose sum is σ = 11778307200. Its totient is φ = 2799153280.

The previous prime is 6667997639. The next prime is 6667997671.

6667997666 is nontrivially palindromic in base 10.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 6667997596 and 6667997605.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 212531 + ... + 241878.

It is an arithmetic number, because the mean of its divisors is an integer number (368072100).

Almost surely, 2^6667997666 is an apocalyptic number.

6667997666 is a deficient number, since it is larger than the sum of its proper divisors (5110309534).

6667997666 is a wasteful number, since it uses less digits than its factorization.

6667997666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454474.

The product of its digits is 185177664, while the sum is 68.

The square root of 6667997666 is about 81657.8083590296. The cubic root of 6667997666 is about 1882.1973012602.

The spelling of 6667997666 in words is "six billion, six hundred sixty-seven million, nine hundred ninety-seven thousand, six hundred sixty-six".