206780491 has 2 divisors, whose sum is σ = 206780492. Its totient is φ = 206780490.

The previous prime is 206780489. The next prime is 206780501. The reversal of 206780491 is 194087602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 206780491 - 2¹ = 206780489 is a prime.

Together with 206780489, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 206780491.

It is not a weakly prime, because it can be changed into another prime (206780891) 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 as a sum of consecutive naturals, namely, 103390245 + 103390246.

It is an arithmetic number, because the mean of its divisors is an integer number (103390246).

Almost surely, 2^206780491 is an apocalyptic number.

206780491 is a deficient number, since it is larger than the sum of its proper divisors (1).

206780491 is an equidigital number, since it uses as much as digits as its factorization.

206780491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 206780491 is about 14379.8640814161. The cubic root of 206780491 is about 591.3389975493.

The spelling of 206780491 in words is "two hundred six million, seven hundred eighty thousand, four hundred ninety-one".