206861749 has 2 divisors, whose sum is σ = 206861750. Its totient is φ = 206861748.

The previous prime is 206861741. The next prime is 206861771. The reversal of 206861749 is 947168602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 193488100 + 13373649 = 13910^2 + 3657^2 .

It is a cyclic number.

It is not a de Polignac number, because 206861749 - 2³ = 206861741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206861741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103430874 + 103430875.

It is an arithmetic number, because the mean of its divisors is an integer number (103430875).

Almost surely, 2^206861749 is an apocalyptic number.

It is an amenable number.

206861749 is a deficient number, since it is larger than the sum of its proper divisors (1).

206861749 is an equidigital number, since it uses as much as digits as its factorization.

206861749 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 145152, while the sum is 43.

The square root of 206861749 is about 14382.6892130783. The cubic root of 206861749 is about 591.4164463957.

The spelling of 206861749 in words is "two hundred six million, eight hundred sixty-one thousand, seven hundred forty-nine".