206313521 has 2 divisors, whose sum is σ = 206313522. Its totient is φ = 206313520.

The previous prime is 206313487. The next prime is 206313551. The reversal of 206313521 is 125313602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 164839921 + 41473600 = 12839^2 + 6440^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-206313521 is a prime.

It is a Chen prime.

It is equal to p_11409035 and since 206313521 and 11409035 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (206313551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103156760 + 103156761.

It is an arithmetic number, because the mean of its divisors is an integer number (103156761).

Almost surely, 2^206313521 is an apocalyptic number.

It is an amenable number.

206313521 is a deficient number, since it is larger than the sum of its proper divisors (1).

206313521 is an equidigital number, since it uses as much as digits as its factorization.

206313521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 206313521 is about 14363.6179634520. The cubic root of 206313521 is about 590.8935240303.

The spelling of 206313521 in words is "two hundred six million, three hundred thirteen thousand, five hundred twenty-one".