20165666 has 16 divisors (see below), whose sum is σ = 31500024. Its totient is φ = 9673344.

The previous prime is 20165659. The next prime is 20165671. The reversal of 20165666 is 66656102.

It can be written as a sum of positive squares in 4 ways, for example, as 19936225 + 229441 = 4465^2 + 479^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3536 + ... + 7268.

Almost surely, 2^20165666 is an apocalyptic number.

20165666 is a deficient number, since it is larger than the sum of its proper divisors (11334358).

20165666 is a wasteful number, since it uses less digits than its factorization.

20165666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3845.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 20165666 is about 4490.6197790505. The cubic root of 20165666 is about 272.1891795950.

The spelling of 20165666 in words is "twenty million, one hundred sixty-five thousand, six hundred sixty-six".