208940861 has 2 divisors, whose sum is σ = 208940862. Its totient is φ = 208940860.

The previous prime is 208940839. The next prime is 208940867. The reversal of 208940861 is 168049802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 193488100 + 15452761 = 13910^2 + 3931^2 .

It is a cyclic number.

It is not a de Polignac number, because 208940861 - 2¹⁴ = 208924477 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (208940867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104470430 + 104470431.

It is an arithmetic number, because the mean of its divisors is an integer number (104470431).

Almost surely, 2^208940861 is an apocalyptic number.

It is an amenable number.

208940861 is a deficient number, since it is larger than the sum of its proper divisors (1).

208940861 is an equidigital number, since it uses as much as digits as its factorization.

208940861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 208940861 is about 14454.7867850066. The cubic root of 208940861 is about 593.3912344777.

The spelling of 208940861 in words is "two hundred eight million, nine hundred forty thousand, eight hundred sixty-one".