206598911221 has 2 divisors, whose sum is σ = 206598911222. Its totient is φ = 206598911220.

The previous prime is 206598911219. The next prime is 206598911231. The reversal of 206598911221 is 122119895602.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 169590770596 + 37008140625 = 411814^2 + 192375^2 .

It is a cyclic number.

It is not a de Polignac number, because 206598911221 - 2¹ = 206598911219 is a prime.

It is a super-2 number, since 2×206598911221² (a number of 23 digits) contains 22 as substring.

Together with 206598911219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206598911201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103299455610 + 103299455611.

It is an arithmetic number, because the mean of its divisors is an integer number (103299455611).

Almost surely, 2^206598911221 is an apocalyptic number.

It is an amenable number.

206598911221 is a deficient number, since it is larger than the sum of its proper divisors (1).

206598911221 is an equidigital number, since it uses as much as digits as its factorization.

206598911221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 155520, while the sum is 46.

The spelling of 206598911221 in words is "two hundred six billion, five hundred ninety-eight million, nine hundred eleven thousand, two hundred twenty-one".