66640421120 has 576 divisors, whose sum is σ = 203875951104. Its totient is φ = 20313538560.

The previous prime is 66640421119. The next prime is 66640421137. The reversal of 66640421120 is 2112404666.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 589738184 + ... + 589738296.

It is an arithmetic number, because the mean of its divisors is an integer number (353951304).

Almost surely, 2^66640421120 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 66640421120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101937975552).

66640421120 is an abundant number, since it is smaller than the sum of its proper divisors (137235529984).

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

66640421120 is a wasteful number, since it uses less digits than its factorization.

66640421120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298 (or 284 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 32.

Adding to 66640421120 its reverse (2112404666), we get a palindrome (68752825786).

The spelling of 66640421120 in words is "sixty-six billion, six hundred forty million, four hundred twenty-one thousand, one hundred twenty".