666651106668 has 12 divisors (see below), whose sum is σ = 1555519248920. Its totient is φ = 222217035552.

The previous prime is 666651106663. The next prime is 666651106673. The reversal of 666651106668 is 866601156666.

666651106668 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (666651106663) and next prime (666651106673).

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×666651106668² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (666651106661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27777129433 + ... + 27777129456.

Almost surely, 2^666651106668 is an apocalyptic number.

It is an amenable number.

666651106668 is an abundant number, since it is smaller than the sum of its proper divisors (888868142252).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666651106668 is a wasteful number, since it uses less digits than its factorization.

666651106668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55554258896 (or 55554258894 counting only the distinct ones).

The product of its (nonzero) digits is 11197440, while the sum is 57.

The spelling of 666651106668 in words is "six hundred sixty-six billion, six hundred fifty-one million, one hundred six thousand, six hundred sixty-eight".