210720640 has 256 divisors, whose sum is σ = 603187200. Its totient is φ = 69672960.

The previous prime is 210720623. The next prime is 210720647. The reversal of 210720640 is 46027012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210720647) 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, 4900459 + ... + 4900501.

It is an arithmetic number, because the mean of its divisors is an integer number (2356200).

Almost surely, 2^210720640 is an apocalyptic number.

210720640 is a gapful number since it is divisible by the number (20) 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 210720640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (301593600).

210720640 is an abundant number, since it is smaller than the sum of its proper divisors (392466560).

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

210720640 is a wasteful number, since it uses less digits than its factorization.

210720640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 210720640 is about 14516.2198936224. The cubic root of 210720640 is about 595.0713282189.

Adding to 210720640 its reverse (46027012), we get a palindrome (256747652).

The spelling of 210720640 in words is "two hundred ten million, seven hundred twenty thousand, six hundred forty".