647244220 has 48 divisors (see below), whose sum is σ = 1559517120. Its totient is φ = 221036544.

The previous prime is 647244217. The next prime is 647244233. The reversal of 647244220 is 22442746.

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, 26986 + ... + 44974.

It is an arithmetic number, because the mean of its divisors is an integer number (32489940).

Almost surely, 2^647244220 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 647244220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (779758560).

647244220 is an abundant number, since it is smaller than the sum of its proper divisors (912272900).

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

647244220 is a wasteful number, since it uses less digits than its factorization.

647244220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18262 (or 18260 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 31.

The square root of 647244220 is about 25440.9948704841. The cubic root of 647244220 is about 865.0131843358.

Adding to 647244220 its reverse (22442746), we get a palindrome (669686966).

The spelling of 647244220 in words is "six hundred forty-seven million, two hundred forty-four thousand, two hundred twenty".