20500506 has 128 divisors (see below), whose sum is σ = 54432000. Its totient is φ = 5660928.

The previous prime is 20500483. The next prime is 20500511. The reversal of 20500506 is 60500502.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 386776 + ... + 386828.

It is an arithmetic number, because the mean of its divisors is an integer number (425250).

Almost surely, 2^20500506 is an apocalyptic number.

20500506 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 20500506, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27216000).

20500506 is an abundant number, since it is smaller than the sum of its proper divisors (33931494).

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

20500506 is a wasteful number, since it uses less digits than its factorization.

20500506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The square root of 20500506 is about 4527.7484470761. The cubic root of 20500506 is about 273.6874355052.

The spelling of 20500506 in words is "twenty million, five hundred thousand, five hundred six".