66165660 has 240 divisors, whose sum is σ = 234178560. Its totient is φ = 15500160.

The previous prime is 66165653. The next prime is 66165679. The reversal of 66165660 is 6656166.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 837501 + ... + 837579.

It is an arithmetic number, because the mean of its divisors is an integer number (975744).

Almost surely, 2^66165660 is an apocalyptic number.

66165660 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 66165660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117089280).

66165660 is an abundant number, since it is smaller than the sum of its proper divisors (168012900).

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

66165660 is a wasteful number, since it uses less digits than its factorization.

66165660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 66165660 is about 8134.2276830686. The cubic root of 66165660 is about 404.4618366465.

The spelling of 66165660 in words is "sixty-six million, one hundred sixty-five thousand, six hundred sixty".