208402121 has 2 divisors, whose sum is σ = 208402122. Its totient is φ = 208402120.

The previous prime is 208402097. The next prime is 208402147. The reversal of 208402121 is 121204802.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 161671225 + 46730896 = 12715^2 + 6836^2 .

It is a cyclic number.

It is not a de Polignac number, because 208402121 - 2¹⁰ = 208401097 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 208402093 and 208402102.

It is not a weakly prime, because it can be changed into another prime (208402151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104201060 + 104201061.

It is an arithmetic number, because the mean of its divisors is an integer number (104201061).

Almost surely, 2^208402121 is an apocalyptic number.

It is an amenable number.

208402121 is a deficient number, since it is larger than the sum of its proper divisors (1).

208402121 is an equidigital number, since it uses as much as digits as its factorization.

208402121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 208402121 is about 14436.1394077503. The cubic root of 208402121 is about 592.8807890063.

Adding to 208402121 its reverse (121204802), we get a palindrome (329606923).

The spelling of 208402121 in words is "two hundred eight million, four hundred two thousand, one hundred twenty-one".