20505104 has 40 divisors (see below), whose sum is σ = 42973440. Its totient is φ = 9445248.

The previous prime is 20505103. The next prime is 20505127. The reversal of 20505104 is 40150502.

It is not an unprimeable number, because it can be changed into a prime (20505101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10337 + ... + 12159.

It is an arithmetic number, because the mean of its divisors is an integer number (1074336).

Almost surely, 2^20505104 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 20505104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21486720).

20505104 is an abundant number, since it is smaller than the sum of its proper divisors (22468336).

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

20505104 is a wasteful number, since it uses less digits than its factorization.

20505104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1887 (or 1881 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 20505104 is about 4528.2561764989. The cubic root of 20505104 is about 273.7078955003.

Adding to 20505104 its reverse (40150502), we get a palindrome (60655606).

The spelling of 20505104 in words is "twenty million, five hundred five thousand, one hundred four".