66561550016600 has 96 divisors (see below), whose sum is σ = 157679911098720. Its totient is φ = 26121541355520.

The previous prime is 66561550016567. The next prime is 66561550016609. The reversal of 66561550016600 is 661005516566.

It is a super-2 number, since 2×66561550016600² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66561550016609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 535269632 + ... + 535393968.

It is an arithmetic number, because the mean of its divisors is an integer number (1642499073945).

Almost surely, 2^{66561550016600} is an apocalyptic number.

It is an amenable number.

66561550016600 is an abundant number, since it is smaller than the sum of its proper divisors (91118361082120).

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

66561550016600 is a wasteful number, since it uses less digits than its factorization.

66561550016600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174909 (or 174900 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 47.

The spelling of 66561550016600 in words is "sixty-six trillion, five hundred sixty-one billion, five hundred fifty million, sixteen thousand, six hundred".