206989957 has 2 divisors, whose sum is σ = 206989958. Its totient is φ = 206989956.

The previous prime is 206989919. The next prime is 206989961. The reversal of 206989957 is 759989602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 191379556 + 15610401 = 13834^2 + 3951^2 .

It is a cyclic number.

It is not a de Polignac number, because 206989957 - 2¹⁵ = 206957189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 206989898 and 206989907.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206980957) 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, 103494978 + 103494979.

It is an arithmetic number, because the mean of its divisors is an integer number (103494979).

Almost surely, 2^206989957 is an apocalyptic number.

It is an amenable number.

206989957 is a deficient number, since it is larger than the sum of its proper divisors (1).

206989957 is an equidigital number, since it uses as much as digits as its factorization.

206989957 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2449440, while the sum is 55.

The square root of 206989957 is about 14387.1455473280. The cubic root of 206989957 is about 591.5386031193.

The spelling of 206989957 in words is "two hundred six million, nine hundred eighty-nine thousand, nine hundred fifty-seven".