208690121 has 4 divisors (see below), whose sum is σ = 209186244. Its totient is φ = 208194000.

The previous prime is 208690117. The next prime is 208690127. The reversal of 208690121 is 121096802.

208690121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 14478025 + 194212096 = 3805^2 + 13936^2 .

It is a cyclic number.

It is not a de Polignac number, because 208690121 - 2² = 208690117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (208690127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 247430 + ... + 248271.

It is an arithmetic number, because the mean of its divisors is an integer number (52296561).

Almost surely, 2^208690121 is an apocalyptic number.

It is an amenable number.

208690121 is a deficient number, since it is larger than the sum of its proper divisors (496123).

208690121 is an equidigital number, since it uses as much as digits as its factorization.

208690121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 496122.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 208690121 is about 14446.1109299354. The cubic root of 208690121 is about 593.1537725877.

The spelling of 208690121 in words is "two hundred eight million, six hundred ninety thousand, one hundred twenty-one".