20105456 has 40 divisors (see below), whose sum is σ = 45041760. Its totient is φ = 8515584.

The previous prime is 20105447. The next prime is 20105479. The reversal of 20105456 is 65450102.

It is a congruent number.

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, 8960 + ... + 10976.

It is an arithmetic number, because the mean of its divisors is an integer number (1126044).

Almost surely, 2^20105456 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20105456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22520880).

20105456 is an abundant number, since it is smaller than the sum of its proper divisors (24936304).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20105456 is a wasteful number, since it uses less digits than its factorization.

20105456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2121 (or 2115 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 20105456 is about 4483.9107930466. The cubic root of 20105456 is about 271.9180116211.

Adding to 20105456 its reverse (65450102), we get a palindrome (85555558).

The spelling of 20105456 in words is "twenty million, one hundred five thousand, four hundred fifty-six".