66914521128 has 576 divisors, whose sum is σ = 233321634000. Its totient is φ = 17269604352.

The previous prime is 66914521099. The next prime is 66914521129. The reversal of 66914521128 is 82112541966.

It can be written as a sum of positive squares in 8 ways, for example, as 9421031844 + 57493489284 = 97062^2 + 239778^2 .

It is not an unprimeable number, because it can be changed into a prime (66914521129) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 689840376 + ... + 689840472.

Almost surely, 2^66914521128 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 66914521128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116660817000).

66914521128 is an abundant number, since it is smaller than the sum of its proper divisors (166407112872).

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

66914521128 is a wasteful number, since it uses less digits than its factorization.

66914521128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251 (or 211 counting only the distinct ones).

The product of its digits is 207360, while the sum is 45.

The spelling of 66914521128 in words is "sixty-six billion, nine hundred fourteen million, five hundred twenty-one thousand, one hundred twenty-eight".