66011680 has 96 divisors (see below), whose sum is σ = 188770176. Its totient is φ = 21295104.

The previous prime is 66011657. The next prime is 66011711. The reversal of 66011680 is 8611066.

It is a Harshad number since it is a multiple of its sum of digits (28).

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, 17307 + ... + 20773.

It is an arithmetic number, because the mean of its divisors is an integer number (1966356).

Almost surely, 2^66011680 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 66011680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94385088).

66011680 is an abundant number, since it is smaller than the sum of its proper divisors (122758496).

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

66011680 is a wasteful number, since it uses less digits than its factorization.

66011680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3506 (or 3498 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 66011680 is about 8124.7572271422. The cubic root of 66011680 is about 404.1478398901.

It can be divided in two parts, 6601 and 1680, that added together give a square (8281 = 91²).

The spelling of 66011680 in words is "sixty-six million, eleven thousand, six hundred eighty".