66481856 has 56 divisors (see below), whose sum is σ = 155667456. Its totient is φ = 27567360.

The previous prime is 66481841. The next prime is 66481861. The reversal of 66481856 is 65818466.

It is a tau number, because it is divible by the number of its divisors (56).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11495 + ... + 16281.

It is an arithmetic number, because the mean of its divisors is an integer number (2779776).

Almost surely, 2^66481856 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 66481856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77833728).

66481856 is an abundant number, since it is smaller than the sum of its proper divisors (89185600).

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

66481856 is a wasteful number, since it uses less digits than its factorization.

66481856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4837 (or 4827 counting only the distinct ones).

The product of its digits is 276480, while the sum is 44.

The square root of 66481856 is about 8153.6406592393. The cubic root of 66481856 is about 405.1051010063.

The spelling of 66481856 in words is "sixty-six million, four hundred eighty-one thousand, eight hundred fifty-six".