66555056550 has 48 divisors (see below), whose sum is σ = 170748156240. Its totient is φ = 17136013440.

The previous prime is 66555056537. The next prime is 66555056567. The reversal of 66555056550 is 5565055566.

It is a self number, because there is not a number n which added to its sum of digits gives 66555056550.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7645657 + ... + 7654356.

It is an arithmetic number, because the mean of its divisors is an integer number (3557253255).

Almost surely, 2^66555056550 is an apocalyptic number.

66555056550 is an abundant number, since it is smaller than the sum of its proper divisors (104193099690).

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

66555056550 is a wasteful number, since it uses less digits than its factorization.

66555056550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15300057 (or 15300052 counting only the distinct ones).

The product of its (nonzero) digits is 3375000, while the sum is 48.

The spelling of 66555056550 in words is "sixty-six billion, five hundred fifty-five million, fifty-six thousand, five hundred fifty".