206121017 has 2 divisors, whose sum is σ = 206121018. Its totient is φ = 206121016.

The previous prime is 206121007. The next prime is 206121029. The reversal of 206121017 is 710121602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 140446201 + 65674816 = 11851^2 + 8104^2 .

It is a cyclic number.

It is not a de Polignac number, because 206121017 - 2⁴ = 206121001 is a prime.

It is a super-2 number, since 2×206121017² = 84971747298228578, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 206121017.

It is not a weakly prime, because it can be changed into another prime (206121007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103060508 + 103060509.

It is an arithmetic number, because the mean of its divisors is an integer number (103060509).

Almost surely, 2^206121017 is an apocalyptic number.

It is an amenable number.

206121017 is a deficient number, since it is larger than the sum of its proper divisors (1).

206121017 is an equidigital number, since it uses as much as digits as its factorization.

206121017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 206121017 is about 14356.9153023900. The cubic root of 206121017 is about 590.7096860810.

Adding to 206121017 its reverse (710121602), we get a palindrome (916242619).

The spelling of 206121017 in words is "two hundred six million, one hundred twenty-one thousand, seventeen".