206445521 has 2 divisors, whose sum is σ = 206445522. Its totient is φ = 206445520.

The previous prime is 206445487. The next prime is 206445529. The reversal of 206445521 is 125544602.

206445521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 140754496 + 65691025 = 11864^2 + 8105^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-206445521 is a prime.

It is a super-2 number, since 2×206445521² = 85239506281922882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (206445529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103222760 + 103222761.

It is an arithmetic number, because the mean of its divisors is an integer number (103222761).

Almost surely, 2^206445521 is an apocalyptic number.

It is an amenable number.

206445521 is a deficient number, since it is larger than the sum of its proper divisors (1).

206445521 is an equidigital number, since it uses as much as digits as its factorization.

206445521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9600, while the sum is 29.

The square root of 206445521 is about 14368.2121713176. The cubic root of 206445521 is about 591.0195156381.

The spelling of 206445521 in words is "two hundred six million, four hundred forty-five thousand, five hundred twenty-one".