209551968 has 96 divisors (see below), whose sum is σ = 613720800. Its totient is φ = 69562368.

The previous prime is 209551967. The next prime is 209551973. The reversal of 209551968 is 869155902.

209551968 is a `hidden beast` number, since 2 + 0 + 9 + 551 + 96 + 8 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209551963) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 353080 + ... + 353672.

It is an arithmetic number, because the mean of its divisors is an integer number (6392925).

Almost surely, 2^209551968 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 209551968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (306860400).

209551968 is an abundant number, since it is smaller than the sum of its proper divisors (404168832).

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

209551968 is a wasteful number, since it uses less digits than its factorization.

209551968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1021 (or 1007 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 45.

The square root of 209551968 is about 14475.9099195871. The cubic root of 209551968 is about 593.9691852191.

The spelling of 209551968 in words is "two hundred nine million, five hundred fifty-one thousand, nine hundred sixty-eight".