66415680 has 112 divisors (see below), whose sum is σ = 234330240. Its totient is φ = 17708544.

The previous prime is 66415669. The next prime is 66415709. The reversal of 66415680 is 8651466.

66415680 is a `hidden beast` number, since 6 + 641 + 5 + 6 + 8 + 0 = 666.

66415680 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×66415680² = 8822085099724800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4797 + ... + 12483.

Almost surely, 2^66415680 is an apocalyptic number.

66415680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66415680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117165120).

66415680 is an abundant number, since it is smaller than the sum of its proper divisors (167914560).

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

66415680 is a wasteful number, since it uses less digits than its factorization.

66415680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7713 (or 7697 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 66415680 is about 8149.5815843514. The cubic root of 66415680 is about 404.9706425908.

It can be divided in two parts, 6641 and 5680, that added together give a palindrome (12321).

The spelling of 66415680 in words is "sixty-six million, four hundred fifteen thousand, six hundred eighty".