66656566956 has 48 divisors (see below), whose sum is σ = 178547984384. Its totient is φ = 18959325696.

The previous prime is 66656566937. The next prime is 66656566957. The reversal of 66656566956 is 65966565666.

It is a super-2 number, since 2×66656566956² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66656566957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1760485 + ... + 1797948.

Almost surely, 2^66656566956 is an apocalyptic number.

It is an amenable number.

66656566956 is an abundant number, since it is smaller than the sum of its proper divisors (111891417428).

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

66656566956 is a wasteful number, since it uses less digits than its factorization.

66656566956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3558670 (or 3558668 counting only the distinct ones).

The product of its digits is 314928000, while the sum is 66.

The spelling of 66656566956 in words is "sixty-six billion, six hundred fifty-six million, five hundred sixty-six thousand, nine hundred fifty-six".