66028217256 has 80 divisors (see below), whose sum is σ = 185393066100. Its totient is φ = 21955504896.

The previous prime is 66028217237. The next prime is 66028217279. The reversal of 66028217256 is 65271282066.

66028217256 is a `hidden beast` number, since 6 + 602 + 8 + 2 + 17 + 25 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 51970320900 + 14057896356 = 227970^2 + 118566^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 140466 + ... + 389598.

Almost surely, 2^66028217256 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 66028217256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92696533050).

66028217256 is an abundant number, since it is smaller than the sum of its proper divisors (119364848844).

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

66028217256 is a wasteful number, since it uses less digits than its factorization.

66028217256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249560 (or 249547 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The spelling of 66028217256 in words is "sixty-six billion, twenty-eight million, two hundred seventeen thousand, two hundred fifty-six".