208668640 has 96 divisors (see below), whose sum is σ = 525813120. Its totient is φ = 78027264.

The previous prime is 208668623. The next prime is 208668643. The reversal of 208668640 is 46866802.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 208668593 and 208668602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208668643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 251907 + ... + 252733.

It is an arithmetic number, because the mean of its divisors is an integer number (5477220).

Almost surely, 2^208668640 is an apocalyptic number.

208668640 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 208668640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (262906560).

208668640 is an abundant number, since it is smaller than the sum of its proper divisors (317144480).

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

208668640 is a wasteful number, since it uses less digits than its factorization.

208668640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 944 (or 936 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 40.

The square root of 208668640 is about 14445.3674235029. The cubic root of 208668640 is about 593.1334202853.

The spelling of 208668640 in words is "two hundred eight million, six hundred sixty-eight thousand, six hundred forty".