66642089760 has 288 divisors, whose sum is σ = 232427443248. Its totient is φ = 17381744640.

The previous prime is 66642089729. The next prime is 66642089797. The reversal of 66642089760 is 6798024666.

It can be written as a sum of positive squares in 8 ways, for example, as 42705049104 + 23937040656 = 206652^2 + 154716^2 .

It is a tau number, because it is divible by the number of its divisors (288).

It is a junction number, because it is equal to n+sod(n) for n = 66642089697 and 66642089706.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 28466190 + ... + 28468530.

Almost surely, 2^66642089760 is an apocalyptic number.

66642089760 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66642089760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116213721624).

66642089760 is an abundant number, since it is smaller than the sum of its proper divisors (165785353488).

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

66642089760 is a wasteful number, since it uses less digits than its factorization.

66642089760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2788 (or 2777 counting only the distinct ones).

The product of its (nonzero) digits is 5225472, while the sum is 54.

The spelling of 66642089760 in words is "sixty-six billion, six hundred forty-two million, eighty-nine thousand, seven hundred sixty".