66165690 has 32 divisors (see below), whose sum is σ = 159022080. Its totient is φ = 17619264.

The previous prime is 66165689. The next prime is 66165703. The reversal of 66165690 is 9656166.

It is a super-4 number, since 4×66165690⁴ (a number of 32 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31596 + ... + 33624.

It is an arithmetic number, because the mean of its divisors is an integer number (4969440).

Almost surely, 2^66165690 is an apocalyptic number.

66165690 is an abundant number, since it is smaller than the sum of its proper divisors (92856390).

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

66165690 is a wasteful number, since it uses less digits than its factorization.

66165690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3126.

The product of its (nonzero) digits is 58320, while the sum is 39.

The square root of 66165690 is about 8134.2295271279. The cubic root of 66165690 is about 404.4618977751.

The spelling of 66165690 in words is "sixty-six million, one hundred sixty-five thousand, six hundred ninety".