66543680 has 112 divisors (see below), whose sum is σ = 184440576. Its totient is φ = 22394880.

The previous prime is 66543667. The next prime is 66543709. The reversal of 66543680 is 8634566.

It is a tau number, because it is divible by the number of its divisors (112).

It is a super-2 number, since 2×66543680² = 8856122695884800, which contains 22 as substring.

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, 136397 + ... + 136883.

Almost surely, 2^66543680 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 66543680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92220288).

66543680 is an abundant number, since it is smaller than the sum of its proper divisors (117896896).

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

66543680 is a wasteful number, since it uses less digits than its factorization.

66543680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 572 (or 562 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 38.

The square root of 66543680 is about 8157.4309681419. The cubic root of 66543680 is about 405.2306363016.

The spelling of 66543680 in words is "sixty-six million, five hundred forty-three thousand, six hundred eighty".