208120001 has 4 divisors (see below), whose sum is σ = 220362372. Its totient is φ = 195877632.

The previous prime is 208119997. The next prime is 208120039. The reversal of 208120001 is 100021802.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 128482225 + 79637776 = 11335^2 + 8924^2 .

It is a cyclic number.

It is not a de Polignac number, because 208120001 - 2² = 208119997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (208122001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6121160 + ... + 6121193.

It is an arithmetic number, because the mean of its divisors is an integer number (55090593).

Almost surely, 2^208120001 is an apocalyptic number.

It is an amenable number.

208120001 is a deficient number, since it is larger than the sum of its proper divisors (12242371).

208120001 is a wasteful number, since it uses less digits than its factorization.

208120001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12242370.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 208120001 is about 14426.3647881232. The cubic root of 208120001 is about 592.6131348822.

Adding to 208120001 its reverse (100021802), we get a palindrome (308141803).

The spelling of 208120001 in words is "two hundred eight million, one hundred twenty thousand, one".