646044020 has 48 divisors (see below), whose sum is σ = 1410393600. Its totient is φ = 248277120.

The previous prime is 646043989. The next prime is 646044031. The reversal of 646044020 is 20440646.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 119741 + ... + 125019.

It is an arithmetic number, because the mean of its divisors is an integer number (29383200).

Almost surely, 2^646044020 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 646044020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (705196800).

646044020 is an abundant number, since it is smaller than the sum of its proper divisors (764349580).

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

646044020 is a wasteful number, since it uses less digits than its factorization.

646044020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5528 (or 5526 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 26.

The square root of 646044020 is about 25417.3960113935. The cubic root of 646044020 is about 864.4781821598.

Adding to 646044020 its reverse (20440646), we get a palindrome (666484666).

The spelling of 646044020 in words is "six hundred forty-six million, forty-four thousand, twenty".