206221360261 has 6 divisors (see below), whose sum is σ = 239890153830. Its totient is φ = 176761165896.

The previous prime is 206221360237. The next prime is 206221360283. The reversal of 206221360261 is 162063122602.

It can be written as a sum of positive squares in only one way, i.e., 204801502500 + 1419857761 = 452550^2 + 37681^2 .

It is not a de Polignac number, because 206221360261 - 2¹³ = 206221352069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206221360661) 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 in 5 ways as a sum of consecutive naturals, for example, 2104299546 + ... + 2104299643.

It is an arithmetic number, because the mean of its divisors is an integer number (39981692305).

Almost surely, 2^206221360261 is an apocalyptic number.

It is an amenable number.

206221360261 is a deficient number, since it is larger than the sum of its proper divisors (33668793569).

206221360261 is an equidigital number, since it uses as much as digits as its factorization.

206221360261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4208599203 (or 4208599196 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 31.

Adding to 206221360261 its reverse (162063122602), we get a palindrome (368284482863).

The spelling of 206221360261 in words is "two hundred six billion, two hundred twenty-one million, three hundred sixty thousand, two hundred sixty-one".