208421680 has 60 divisors (see below), whose sum is σ = 500900976. Its totient is φ = 80649600.

The previous prime is 208421677. The next prime is 208421723. The reversal of 208421680 is 86124802.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 75525 + ... + 78235.

Almost surely, 2^208421680 is an apocalyptic number.

208421680 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 208421680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (250450488).

208421680 is an abundant number, since it is smaller than the sum of its proper divisors (292479296).

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

208421680 is a wasteful number, since it uses less digits than its factorization.

208421680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2786 (or 2749 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 208421680 is about 14436.8168236630. The cubic root of 208421680 is about 592.8993361506.

It can be divided in two parts, 20842 and 1680, that added together give a palindrome (22522).

The spelling of 208421680 in words is "two hundred eight million, four hundred twenty-one thousand, six hundred eighty".