66545642560 has 168 divisors, whose sum is σ = 171771914520. Its totient is φ = 24534171648.

The previous prime is 66545642549. The next prime is 66545642563. The reversal of 66545642560 is 6524654566.

It can be written as a sum of positive squares in 4 ways, for example, as 14492307456 + 52053335104 = 120384^2 + 228152^2 .

It is not an unprimeable number, because it can be changed into a prime (66545642563) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4266456 + ... + 4282024.

Almost surely, 2^66545642560 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 66545642560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85885957260).

66545642560 is an abundant number, since it is smaller than the sum of its proper divisors (105226271960).

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

66545642560 is a wasteful number, since it uses less digits than its factorization.

66545642560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15661 (or 15632 counting only the distinct ones).

The product of its (nonzero) digits is 5184000, while the sum is 49.

The spelling of 66545642560 in words is "sixty-six billion, five hundred forty-five million, six hundred forty-two thousand, five hundred sixty".