66471980 has 48 divisors (see below), whose sum is σ = 146768160. Its totient is φ = 25256448.

The previous prime is 66471971. The next prime is 66472009. The reversal of 66471980 is 8917466.

66471980 = T₃₂₇ + T₃₂₈ + ... + T₇₅₆.

66471980 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30776 + ... + 32864.

It is an arithmetic number, because the mean of its divisors is an integer number (3057670).

Almost surely, 2^66471980 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66471980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (73384080).

66471980 is an abundant number, since it is smaller than the sum of its proper divisors (80296180).

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

66471980 is a wasteful number, since it uses less digits than its factorization.

66471980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2178 (or 2176 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 66471980 is about 8153.0350177097. The cubic root of 66471980 is about 405.0850403143.

The spelling of 66471980 in words is "sixty-six million, four hundred seventy-one thousand, nine hundred eighty".