66517760 has 72 divisors (see below), whose sum is σ = 160830096. Its totient is φ = 26357760.

The previous prime is 66517757. The next prime is 66517783. The reversal of 66517760 is 6771566.

It is a super-2 number, since 2×66517760² = 8849224790835200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 200795 + ... + 201125.

Almost surely, 2^66517760 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 66517760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80415048).

66517760 is an abundant number, since it is smaller than the sum of its proper divisors (94312336).

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

66517760 is a wasteful number, since it uses less digits than its factorization.

66517760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509 (or 495 counting only the distinct ones).

The product of its (nonzero) digits is 52920, while the sum is 38.

The square root of 66517760 is about 8155.8420779218. The cubic root of 66517760 is about 405.1780145141.

The spelling of 66517760 in words is "sixty-six million, five hundred seventeen thousand, seven hundred sixty".