66659672520 has 384 divisors, whose sum is σ = 261684172800. Its totient is φ = 15235516800.

The previous prime is 66659672489. The next prime is 66659672567. The reversal of 66659672520 is 2527695666.

66659672520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4278745 + ... + 4294295.

It is an arithmetic number, because the mean of its divisors is an integer number (681469200).

Almost surely, 2^66659672520 is an apocalyptic number.

66659672520 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 66659672520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130842086400).

66659672520 is an abundant number, since it is smaller than the sum of its proper divisors (195024500280).

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

66659672520 is a wasteful number, since it uses less digits than its factorization.

66659672520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15597 (or 15568 counting only the distinct ones).

The product of its (nonzero) digits is 8164800, while the sum is 54.

The spelling of 66659672520 in words is "sixty-six billion, six hundred fifty-nine million, six hundred seventy-two thousand, five hundred twenty".