20611166 has 4 divisors (see below), whose sum is σ = 30916752. Its totient is φ = 10305582.

The previous prime is 20611153. The next prime is 20611169. The reversal of 20611166 is 66111602.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20611169) by changing a digit.

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 as a sum of consecutive naturals, namely, 5152790 + ... + 5152793.

It is an arithmetic number, because the mean of its divisors is an integer number (7729188).

Almost surely, 2^20611166 is an apocalyptic number.

20611166 is a deficient number, since it is larger than the sum of its proper divisors (10305586).

20611166 is a wasteful number, since it uses less digits than its factorization.

20611166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10305585.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 20611166 is about 4539.9522023916. The cubic root of 20611166 is about 274.1789993108.

Adding to 20611166 its reverse (66111602), we get a palindrome (86722768).

The spelling of 20611166 in words is "twenty million, six hundred eleven thousand, one hundred sixty-six".