208051021 has 2 divisors, whose sum is σ = 208051022. Its totient is φ = 208051020.

The previous prime is 208051001. The next prime is 208051057. The reversal of 208051021 is 120150802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 179854921 + 28196100 = 13411^2 + 5310^2 .

It is a cyclic number.

It is not a de Polignac number, because 208051021 - 2⁵ = 208050989 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 208051021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (208051001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104025510 + 104025511.

It is an arithmetic number, because the mean of its divisors is an integer number (104025511).

Almost surely, 2^208051021 is an apocalyptic number.

It is an amenable number.

208051021 is a deficient number, since it is larger than the sum of its proper divisors (1).

208051021 is an equidigital number, since it uses as much as digits as its factorization.

208051021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 208051021 is about 14423.9738283179. The cubic root of 208051021 is about 592.5476550773.

The spelling of 208051021 in words is "two hundred eight million, fifty-one thousand, twenty-one".