206270021 has 2 divisors, whose sum is σ = 206270022. Its totient is φ = 206270020.

The previous prime is 206269991. The next prime is 206270033. The reversal of 206270021 is 120072602.

206270021 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., 158508100 + 47761921 = 12590^2 + 6911^2 .

It is a cyclic number.

It is not a de Polignac number, because 206270021 - 2¹⁸ = 206007877 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 206269975 and 206270002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206270321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103135010 + 103135011.

It is an arithmetic number, because the mean of its divisors is an integer number (103135011).

Almost surely, 2^206270021 is an apocalyptic number.

It is an amenable number.

206270021 is a deficient number, since it is larger than the sum of its proper divisors (1).

206270021 is an equidigital number, since it uses as much as digits as its factorization.

206270021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 206270021 is about 14362.1036411801. The cubic root of 206270021 is about 590.8519922960.

The spelling of 206270021 in words is "two hundred six million, two hundred seventy thousand, twenty-one".