20505276 has 72 divisors (see below), whose sum is σ = 57670704. Its totient is φ = 6090240.

The previous prime is 20505269. The next prime is 20505307. The reversal of 20505276 is 67250502.

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 23 ways as a sum of consecutive naturals, for example, 20500 + ... + 21476.

It is an arithmetic number, because the mean of its divisors is an integer number (800982).

Almost surely, 2^20505276 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 20505276, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28835352).

20505276 is an abundant number, since it is smaller than the sum of its proper divisors (37165428).

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

20505276 is a wasteful number, since it uses less digits than its factorization.

20505276 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1051 (or 1046 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 27.

The square root of 20505276 is about 4528.2751683174. The cubic root of 20505276 is about 273.7086607996.

Adding to 20505276 its reverse (67250502), we get a palindrome (87755778).

The spelling of 20505276 in words is "twenty million, five hundred five thousand, two hundred seventy-six".