206021021 has 2 divisors, whose sum is σ = 206021022. Its totient is φ = 206021020.

The previous prime is 206020993. The next prime is 206021059. The reversal of 206021021 is 120120602.

206021021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 118504996 + 87516025 = 10886^2 + 9355^2 .

It is a cyclic number.

It is not a de Polignac number, because 206021021 - 2¹⁴ = 206004637 is a prime.

It is a super-2 number, since 2×206021021² = 84889322187764882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 206020987 and 206021005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206041021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103010510 + 103010511.

It is an arithmetic number, because the mean of its divisors is an integer number (103010511).

Almost surely, 2^206021021 is an apocalyptic number.

It is an amenable number.

206021021 is a deficient number, since it is larger than the sum of its proper divisors (1).

206021021 is an equidigital number, since it uses as much as digits as its factorization.

206021021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 206021021 is about 14353.4323769613. The cubic root of 206021021 is about 590.6141464780.

Adding to 206021021 its reverse (120120602), we get a palindrome (326141623).

The spelling of 206021021 in words is "two hundred six million, twenty-one thousand, twenty-one".