206217961 has 2 divisors, whose sum is σ = 206217962. Its totient is φ = 206217960.

The previous prime is 206217943. The next prime is 206217967. The reversal of 206217961 is 169712602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 169494361 + 36723600 = 13019^2 + 6060^2 .

It is a cyclic number.

It is not a de Polignac number, because 206217961 - 2¹¹ = 206215913 is a prime.

It is not a weakly prime, because it can be changed into another prime (206217967) 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, 103108980 + 103108981.

It is an arithmetic number, because the mean of its divisors is an integer number (103108981).

Almost surely, 2^206217961 is an apocalyptic number.

It is an amenable number.

206217961 is a deficient number, since it is larger than the sum of its proper divisors (1).

206217961 is an equidigital number, since it uses as much as digits as its factorization.

206217961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 206217961 is about 14360.2911182190. The cubic root of 206217961 is about 590.8022802038.

It can be divided in two parts, 20621 and 7961, that added together give a palindrome (28582).

The spelling of 206217961 in words is "two hundred six million, two hundred seventeen thousand, nine hundred sixty-one".