20112905 has 4 divisors (see below), whose sum is σ = 24135492. Its totient is φ = 16090320.

The previous prime is 20112899. The next prime is 20112907. The reversal of 20112905 is 50921102.

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

It can be written as a sum of positive squares in 2 ways, for example, as 12166144 + 7946761 = 3488^2 + 2819^2 .

It is not a de Polignac number, because 20112905 - 2⁴ = 20112889 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20112907) 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 3 ways as a sum of consecutive naturals, for example, 2011286 + ... + 2011295.

It is an arithmetic number, because the mean of its divisors is an integer number (6033873).

Almost surely, 2^20112905 is an apocalyptic number.

It is an amenable number.

20112905 is a deficient number, since it is larger than the sum of its proper divisors (4022587).

20112905 is an equidigital number, since it uses as much as digits as its factorization.

20112905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4022586.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 20112905 is about 4484.7413526312. The cubic root of 20112905 is about 271.9515890270.

The spelling of 20112905 in words is "twenty million, one hundred twelve thousand, nine hundred five".