66655855666 has 16 divisors (see below), whose sum is σ = 100441088640. Its totient is φ = 33175724400.

The previous prime is 66655855661. The next prime is 66655855687.

66655855666 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 66655855598 and 66655855607.

It is not an unprimeable number, because it can be changed into a prime (66655855661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 525015 + ... + 639493.

It is an arithmetic number, because the mean of its divisors is an integer number (6277568040).

Almost surely, 2^66655855666 is an apocalyptic number.

66655855666 is a deficient number, since it is larger than the sum of its proper divisors (33785232974).

66655855666 is a wasteful number, since it uses less digits than its factorization.

66655855666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115809.

The product of its digits is 233280000, while the sum is 64.

The spelling of 66655855666 in words is "sixty-six billion, six hundred fifty-five million, eight hundred fifty-five thousand, six hundred sixty-six".