66128500 has 24 divisors (see below), whose sum is σ = 144425736. Its totient is φ = 26451200.

The previous prime is 66128479. The next prime is 66128527. The reversal of 66128500 is 582166.

66128500 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 226576 + 65901924 = 476^2 + 8118^2 .

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 65629 + ... + 66628.

It is an arithmetic number, because the mean of its divisors is an integer number (6017739).

Almost surely, 2^66128500 is an apocalyptic number.

It is an amenable number.

66128500 is an abundant number, since it is smaller than the sum of its proper divisors (78297236).

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

66128500 is a wasteful number, since it uses less digits than its factorization.

66128500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132276 (or 132264 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 66128500 is about 8131.9431872093. The cubic root of 66128500 is about 404.3861044292.

It can be divided in two parts, 661 and 28500, that added together give a triangular number (29161 = T₂₄₁).

The spelling of 66128500 in words is "sixty-six million, one hundred twenty-eight thousand, five hundred".