664801020 has 120 divisors (see below), whose sum is σ = 2246000064. Its totient is φ = 163638144.

The previous prime is 664801003. The next prime is 664801021. The reversal of 664801020 is 20108466.

664801020 is a `hidden beast` number, since 6 + 648 + 0 + 10 + 2 + 0 = 666.

664801020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664801021) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 5277 + ... + 36843.

Almost surely, 2^664801020 is an apocalyptic number.

664801020 is a gapful number since it is divisible by the number (60) 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 664801020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1123000032).

664801020 is an abundant number, since it is smaller than the sum of its proper divisors (1581199044).

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

664801020 is a wasteful number, since it uses less digits than its factorization.

664801020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31601 (or 31590 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 664801020 is about 25783.7355710921. The cubic root of 664801020 is about 872.7648071570.

Adding to 664801020 its reverse (20108466), we get a palindrome (684909486).

The spelling of 664801020 in words is "six hundred sixty-four million, eight hundred one thousand, twenty".