66556077065566 has 32 divisors (see below), whose sum is σ = 115461100212192. Its totient is φ = 28437462466560.

The previous prime is 66556077065561. The next prime is 66556077065567.

66556077065566 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×66556077065566² (a number of 28 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66556077065495 and 66556077065504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66556077065561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 111343971 + ... + 111940126.

It is an arithmetic number, because the mean of its divisors is an integer number (3608159381631).

Almost surely, 2^{66556077065566} is an apocalyptic number.

66556077065566 is a deficient number, since it is larger than the sum of its proper divisors (48905023146626).

66556077065566 is a wasteful number, since it uses less digits than its factorization.

66556077065566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223284924.

The product of its (nonzero) digits is 1428840000, while the sum is 70.

The spelling of 66556077065566 in words is "sixty-six trillion, five hundred fifty-six billion, seventy-seven million, sixty-five thousand, five hundred sixty-six".