66055221216558 has 48 divisors (see below), whose sum is σ = 163654641386496. Its totient is φ = 18862612842960.

The previous prime is 66055221216557. The next prime is 66055221216581. The reversal of 66055221216558 is 85561212255066.

66055221216558 is a `hidden beast` number, since 6 + 6 + 0 + 5 + 52 + 21 + 2 + 16 + 558 = 666.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66055221216557) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 142928166 + ... + 143389577.

It is an arithmetic number, because the mean of its divisors is an integer number (3409471695552).

Almost surely, 2^{66055221216558} is an apocalyptic number.

66055221216558 is an abundant number, since it is smaller than the sum of its proper divisors (97599420169938).

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

66055221216558 is a wasteful number, since it uses less digits than its factorization.

66055221216558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 286319589 (or 286319586 counting only the distinct ones).

The product of its (nonzero) digits is 8640000, while the sum is 54.

The spelling of 66055221216558 in words is "sixty-six trillion, fifty-five billion, two hundred twenty-one million, two hundred sixteen thousand, five hundred fifty-eight".