66055221216556 has 48 divisors (see below), whose sum is σ = 135812115532800. Its totient is φ = 27714196595520.

The previous prime is 66055221216547. The next prime is 66055221216557. The reversal of 66055221216556 is 65561212255066.

It is a super-2 number, since 2×66055221216556² (a number of 28 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (52).

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 15 ways as a sum of consecutive naturals, for example, 9770295 + ... + 15085393.

It is an arithmetic number, because the mean of its divisors is an integer number (2829419073600).

Almost surely, 2^{66055221216556} is an apocalyptic number.

It is an amenable number.

66055221216556 is an abundant number, since it is smaller than the sum of its proper divisors (69756894316244).

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

66055221216556 is a wasteful number, since it uses less digits than its factorization.

66055221216556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5336854 (or 5336852 counting only the distinct ones).

The product of its (nonzero) digits is 6480000, while the sum is 52.

The spelling of 66055221216556 in words is "sixty-six trillion, fifty-five billion, two hundred twenty-one million, two hundred sixteen thousand, five hundred fifty-six".