66571155520 has 112 divisors (see below), whose sum is σ = 162538714800. Its totient is φ = 25955041280.

The previous prime is 66571155517. The next prime is 66571155557. The reversal of 66571155520 is 2555117566.

It can be written as a sum of positive squares in 8 ways, for example, as 39232517184 + 27338638336 = 198072^2 + 165344^2 .

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, 22420596 + ... + 22423564.

It is an arithmetic number, because the mean of its divisors is an integer number (1451238525).

Almost surely, 2^66571155520 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 66571155520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81269357400).

66571155520 is an abundant number, since it is smaller than the sum of its proper divisors (95967559280).

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

66571155520 is a wasteful number, since it uses less digits than its factorization.

66571155520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4736 (or 4726 counting only the distinct ones).

The product of its (nonzero) digits is 315000, while the sum is 43.

The spelling of 66571155520 in words is "sixty-six billion, five hundred seventy-one million, one hundred fifty-five thousand, five hundred twenty".