20506872 has 64 divisors (see below), whose sum is σ = 54236160. Its totient is φ = 6451200.

The previous prime is 20506861. The next prime is 20506873. The reversal of 20506872 is 27860502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20506873) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 31672 + ... + 32312.

It is an arithmetic number, because the mean of its divisors is an integer number (847440).

Almost surely, 2^20506872 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 20506872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27118080).

20506872 is an abundant number, since it is smaller than the sum of its proper divisors (33729288).

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

20506872 is a wasteful number, since it uses less digits than its factorization.

20506872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 724 (or 720 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 20506872 is about 4528.4513909282. The cubic root of 20506872 is about 273.7157618613.

The spelling of 20506872 in words is "twenty million, five hundred six thousand, eight hundred seventy-two".