20104871 has 4 divisors (see below), whose sum is σ = 20191392. Its totient is φ = 20018352.

The previous prime is 20104867. The next prime is 20104901. The reversal of 20104871 is 17840102.

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

It is a cyclic number.

It is not a de Polignac number, because 20104871 - 2² = 20104867 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20104811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42911 + ... + 43376.

It is an arithmetic number, because the mean of its divisors is an integer number (5047848).

Almost surely, 2^20104871 is an apocalyptic number.

20104871 is a deficient number, since it is larger than the sum of its proper divisors (86521).

20104871 is an equidigital number, since it uses as much as digits as its factorization.

20104871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86520.

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 20104871 is about 4483.8455593385. The cubic root of 20104871 is about 271.9153743008.

Adding to 20104871 its reverse (17840102), we get a palindrome (37944973).

The spelling of 20104871 in words is "twenty million, one hundred four thousand, eight hundred seventy-one".