209725056 has 96 divisors (see below), whose sum is σ = 639065700. Its totient is φ = 65789952.

The previous prime is 209725051. The next prime is 209725079. The reversal of 209725056 is 650527902.

209725056 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 171086400 + 38638656 = 13080^2 + 6216^2 .

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×209725056² = 87969198228406272, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 209725056.

It is not an unprimeable number, because it can be changed into a prime (209725051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14230 + ... + 24938.

Almost surely, 2^209725056 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 209725056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (319532850).

209725056 is an abundant number, since it is smaller than the sum of its proper divisors (429340644).

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

209725056 is a wasteful number, since it uses less digits than its factorization.

209725056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10746 (or 10731 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 36.

The square root of 209725056 is about 14481.8871698408. The cubic root of 209725056 is about 594.1326779092.

The spelling of 209725056 in words is "two hundred nine million, seven hundred twenty-five thousand, fifty-six".