20891104 has 36 divisors (see below), whose sum is σ = 44548056. Its totient is φ = 9639552.

The previous prime is 20891093. The next prime is 20891131. The reversal of 20891104 is 40119802.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 3477 + ... + 7339.

It is an arithmetic number, because the mean of its divisors is an integer number (1237446).

Almost surely, 2^20891104 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 20891104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22274028).

20891104 is an abundant number, since it is smaller than the sum of its proper divisors (23656952).

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

20891104 is a wasteful number, since it uses less digits than its factorization.

20891104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3899 (or 3878 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 20891104 is about 4570.6787242159. The cubic root of 20891104 is about 275.4147087270.

The spelling of 20891104 in words is "twenty million, eight hundred ninety-one thousand, one hundred four".