208421136 has 120 divisors (see below), whose sum is σ = 727257024. Its totient is φ = 54132480.

The previous prime is 208421119. The next prime is 208421137. The reversal of 208421136 is 631124802.

208421136 is a `hidden beast` number, since 208 + 421 + 1 + 36 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208421137) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1690 + ... + 20486.

Almost surely, 2^208421136 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 208421136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (363628512).

208421136 is an abundant number, since it is smaller than the sum of its proper divisors (518835888).

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

208421136 is a wasteful number, since it uses less digits than its factorization.

208421136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18829 (or 18820 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 208421136 is about 14436.7979829324. The cubic root of 208421136 is about 592.8988203093.

Adding to 208421136 its reverse (631124802), we get a palindrome (839545938).

It can be divided in two parts, 2084 and 21136, that added together give a triangular number (23220 = T₂₁₅).

The spelling of 208421136 in words is "two hundred eight million, four hundred twenty-one thousand, one hundred thirty-six".