208628640 has 144 divisors (see below), whose sum is σ = 776726496. Its totient is φ = 50572800.

The previous prime is 208628633. The next prime is 208628677. The reversal of 208628640 is 46826802.

208628640 is a `hidden beast` number, since 2 + 0 + 8 + 6 + 2 + 8 + 640 = 666.

208628640 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 208628595 and 208628604.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9255 + ... + 22425.

It is an arithmetic number, because the mean of its divisors is an integer number (5393934).

Almost surely, 2^208628640 is an apocalyptic number.

208628640 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 208628640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (388363248).

208628640 is an abundant number, since it is smaller than the sum of its proper divisors (568097856).

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

208628640 is a wasteful number, since it uses less digits than its factorization.

208628640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13203 (or 13192 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The square root of 208628640 is about 14443.9828302307. The cubic root of 208628640 is about 593.0955183227.

The spelling of 208628640 in words is "two hundred eight million, six hundred twenty-eight thousand, six hundred forty".