206031521 has 2 divisors, whose sum is σ = 206031522. Its totient is φ = 206031520.

The previous prime is 206031491. The next prime is 206031523. The reversal of 206031521 is 125130602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 188925025 + 17106496 = 13745^2 + 4136^2 .

It is a cyclic number.

It is not a de Polignac number, because 206031521 - 2²² = 201837217 is a prime.

Together with 206031523, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 206031493 and 206031502.

It is not a weakly prime, because it can be changed into another prime (206031523) 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, 103015760 + 103015761.

It is an arithmetic number, because the mean of its divisors is an integer number (103015761).

Almost surely, 2^206031521 is an apocalyptic number.

It is an amenable number.

206031521 is a deficient number, since it is larger than the sum of its proper divisors (1).

206031521 is an equidigital number, since it uses as much as digits as its factorization.

206031521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 206031521 is about 14353.7981384719. The cubic root of 206031521 is about 590.6241799901.

The spelling of 206031521 in words is "two hundred six million, thirty-one thousand, five hundred twenty-one".