20123866 has 16 divisors (see below), whose sum is σ = 35340480. Its totient is φ = 8413920.

The previous prime is 20123861. The next prime is 20123881. The reversal of 20123866 is 66832102.

It is not an unprimeable number, because it can be changed into a prime (20123861) 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 in 7 ways as a sum of consecutive naturals, for example, 16956 + ... + 18103.

It is an arithmetic number, because the mean of its divisors is an integer number (2208780).

Almost surely, 2^20123866 is an apocalyptic number.

20123866 is a deficient number, since it is larger than the sum of its proper divisors (15216614).

20123866 is a wasteful number, since it uses less digits than its factorization.

20123866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35109.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 20123866 is about 4485.9632187525. The cubic root of 20123866 is about 272.0009821908. Note that the first 3 decimals are identical.

Adding to 20123866 its reverse (66832102), we get a palindrome (86955968).

The spelling of 20123866 in words is "twenty million, one hundred twenty-three thousand, eight hundred sixty-six".