206545621 has 2 divisors, whose sum is σ = 206545622. Its totient is φ = 206545620.

The previous prime is 206545571. The next prime is 206545663. The reversal of 206545621 is 126545602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 115132900 + 91412721 = 10730^2 + 9561^2 .

It is a cyclic number.

It is not a de Polignac number, because 206545621 - 2⁹ = 206545109 is a prime.

It is a super-2 number, since 2×206545621² = 85322187108551282, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206545321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103272810 + 103272811.

It is an arithmetic number, because the mean of its divisors is an integer number (103272811).

Almost surely, 2^206545621 is an apocalyptic number.

It is an amenable number.

206545621 is a deficient number, since it is larger than the sum of its proper divisors (1).

206545621 is an equidigital number, since it uses as much as digits as its factorization.

206545621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 206545621 is about 14371.6951331428. The cubic root of 206545621 is about 591.1150234730.

The spelling of 206545621 in words is "two hundred six million, five hundred forty-five thousand, six hundred twenty-one".