663800020 has 96 divisors (see below), whose sum is σ = 1600300800. Its totient is φ = 229115904.

The previous prime is 663799999. The next prime is 663800029. The reversal of 663800020 is 20008366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663800029) 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 31 ways as a sum of consecutive naturals, for example, 790761 + ... + 791599.

It is an arithmetic number, because the mean of its divisors is an integer number (16669800).

Almost surely, 2^663800020 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 663800020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (800150400).

663800020 is an abundant number, since it is smaller than the sum of its proper divisors (936500780).

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

663800020 is a wasteful number, since it uses less digits than its factorization.

663800020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1057 (or 1055 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 663800020 is about 25764.3167966861. The cubic root of 663800020 is about 872.3265424755.

Adding to 663800020 its reverse (20008366), we get a palindrome (683808386).

The spelling of 663800020 in words is "six hundred sixty-three million, eight hundred thousand, twenty".