66428525440 has 128 divisors (see below), whose sum is σ = 170175388320. Its totient is φ = 24706744320.

The previous prime is 66428525437. The next prime is 66428525453. The reversal of 66428525440 is 4452582466.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 866260 + ... + 939820.

Almost surely, 2^66428525440 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 66428525440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85087694160).

66428525440 is an abundant number, since it is smaller than the sum of its proper divisors (103746862880).

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

66428525440 is a wasteful number, since it uses less digits than its factorization.

66428525440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73680 (or 73668 counting only the distinct ones).

The product of its (nonzero) digits is 1843200, while the sum is 46.

It can be divided in two parts, 664285 and 25440, that added together give a triangular number (689725 = T₁₁₇₄).

The spelling of 66428525440 in words is "sixty-six billion, four hundred twenty-eight million, five hundred twenty-five thousand, four hundred forty".