209941056 has 252 divisors, whose sum is σ = 690230268. Its totient is φ = 60622848.

The previous prime is 209941049. The next prime is 209941073. The reversal of 209941056 is 650149902.

It can be written as a sum of positive squares in 2 ways, for example, as 88059456 + 121881600 = 9384^2 + 11040^2 .

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 209941056.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3961126 + ... + 3961178.

It is an arithmetic number, because the mean of its divisors is an integer number (2739009).

Almost surely, 2^209941056 is an apocalyptic number.

209941056 is a gapful number since it is divisible by the number (26) 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 209941056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (345115134).

209941056 is an abundant number, since it is smaller than the sum of its proper divisors (480289212).

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

209941056 is a wasteful number, since it uses less digits than its factorization.

209941056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130 (or 94 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 209941056 is about 14489.3428422410. The cubic root of 209941056 is about 594.3365776063.

The spelling of 209941056 in words is "two hundred nine million, nine hundred forty-one thousand, fifty-six".