66686580 has 288 divisors, whose sum is σ = 239016960. Its totient is φ = 14929920.

The previous prime is 66686569. The next prime is 66686647. The reversal of 66686580 is 8568666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1802322 + ... + 1802358.

It is an arithmetic number, because the mean of its divisors is an integer number (829920).

Almost surely, 2^66686580 is an apocalyptic number.

66686580 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 66686580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119508480).

66686580 is an abundant number, since it is smaller than the sum of its proper divisors (172330380).

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

66686580 is a wasteful number, since it uses less digits than its factorization.

66686580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119 (or 114 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The square root of 66686580 is about 8166.1851558730. The cubic root of 66686580 is about 405.5205013244.

The spelling of 66686580 in words is "sixty-six million, six hundred eighty-six thousand, five hundred eighty".