206991773 has 2 divisors, whose sum is σ = 206991774. Its totient is φ = 206991772.

The previous prime is 206991769. The next prime is 206991797. The reversal of 206991773 is 377199602.

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., 127193284 + 79798489 = 11278^2 + 8933^2 .

It is a cyclic number.

It is not a de Polignac number, because 206991773 - 2² = 206991769 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206961773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103495886 + 103495887.

It is an arithmetic number, because the mean of its divisors is an integer number (103495887).

Almost surely, 2^206991773 is an apocalyptic number.

It is an amenable number.

206991773 is a deficient number, since it is larger than the sum of its proper divisors (1).

206991773 is an equidigital number, since it uses as much as digits as its factorization.

206991773 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 142884, while the sum is 44.

The square root of 206991773 is about 14387.2086590832. The cubic root of 206991773 is about 591.5403330437.

The spelling of 206991773 in words is "two hundred six million, nine hundred ninety-one thousand, seven hundred seventy-three".