20031820 has 24 divisors (see below), whose sum is σ = 42152544. Its totient is φ = 7996416.

The previous prime is 20031799. The next prime is 20031829. The reversal of 20031820 is 2813002.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20031794 and 20031803.

It is not an unprimeable number, because it can be changed into a prime (20031829) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 15852 + ... + 17068.

It is an arithmetic number, because the mean of its divisors is an integer number (1756356).

Almost surely, 2^20031820 is an apocalyptic number.

20031820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20031820 is an abundant number, since it is smaller than the sum of its proper divisors (22120724).

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

20031820 is a wasteful number, since it uses less digits than its factorization.

20031820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2049 (or 2047 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 20031820 is about 4475.6921252472. The cubic root of 20031820 is about 271.5856399972.

Adding to 20031820 its reverse (2813002), we get a palindrome (22844822).

The spelling of 20031820 in words is "twenty million, thirty-one thousand, eight hundred twenty".