66109680 has 240 divisors, whose sum is σ = 273524160. Its totient is φ = 13934592.

The previous prime is 66109679. The next prime is 66109691. The reversal of 66109680 is 8690166.

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 65016 + ... + 66024.

It is an arithmetic number, because the mean of its divisors is an integer number (1139684).

Almost surely, 2^66109680 is an apocalyptic number.

66109680 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 66109680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136762080).

66109680 is an abundant number, since it is smaller than the sum of its proper divisors (207414480).

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

66109680 is a wasteful number, since it uses less digits than its factorization.

66109680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1048 (or 1039 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 66109680 is about 8130.7859398708. The cubic root of 66109680 is about 404.3477383764.

It can be divided in two parts, 6610 and 9680, that added together give a triangular number (16290 = T₁₈₀).

The spelling of 66109680 in words is "sixty-six million, one hundred nine thousand, six hundred eighty".