20390500 has 48 divisors (see below), whose sum is σ = 47973744. Its totient is φ = 7526400.

The previous prime is 20390483. The next prime is 20390549. The reversal of 20390500 is 509302.

It can be written as a sum of positive squares in 8 ways, for example, as 3481956 + 16908544 = 1866^2 + 4112^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4932 + ... + 8068.

It is an arithmetic number, because the mean of its divisors is an integer number (999453).

Almost surely, 2^20390500 is an apocalyptic number.

20390500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20390500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23986872).

20390500 is an abundant number, since it is smaller than the sum of its proper divisors (27583244).

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

20390500 is a wasteful number, since it uses less digits than its factorization.

20390500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3169 (or 3157 counting only the distinct ones).

The product of its (nonzero) digits is 270, while the sum is 19.

The square root of 20390500 is about 4515.5841261126. The cubic root of 20390500 is about 273.1970204046.

Adding to 20390500 its reverse (509302), we get a palindrome (20899802).

The spelling of 20390500 in words is "twenty million, three hundred ninety thousand, five hundred".