66655638504 has 512 divisors, whose sum is σ = 246951936000. Its totient is φ = 16157159424.

The previous prime is 66655638503. The next prime is 66655638529. The reversal of 66655638504 is 40583655666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (66655638503) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 14366217 + ... + 14370855.

It is an arithmetic number, because the mean of its divisors is an integer number (482328000).

Almost surely, 2^66655638504 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 66655638504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123475968000).

66655638504 is an abundant number, since it is smaller than the sum of its proper divisors (180296297496).

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

66655638504 is a wasteful number, since it uses less digits than its factorization.

66655638504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4734 (or 4724 counting only the distinct ones).

The product of its (nonzero) digits is 15552000, while the sum is 54.

The spelling of 66655638504 in words is "sixty-six billion, six hundred fifty-five million, six hundred thirty-eight thousand, five hundred four".