66550655643 has 16 divisors (see below), whose sum is σ = 90908770176. Its totient is φ = 43280068160.

The previous prime is 66550655629. The next prime is 66550655719. The reversal of 66550655643 is 34655605566.

It is a cyclic number.

It is not a de Polignac number, because 66550655643 - 2²⁰ = 66549607067 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66550655603) 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, 1286680 + ... + 1337402.

It is an arithmetic number, because the mean of its divisors is an integer number (5681798136).

Almost surely, 2^66550655643 is an apocalyptic number.

66550655643 is a deficient number, since it is larger than the sum of its proper divisors (24358114533).

66550655643 is a wasteful number, since it uses less digits than its factorization.

66550655643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61434.

The product of its (nonzero) digits is 9720000, while the sum is 51.

The spelling of 66550655643 in words is "sixty-six billion, five hundred fifty million, six hundred fifty-five thousand, six hundred forty-three".