206240921 has 2 divisors, whose sum is σ = 206240922. Its totient is φ = 206240920.

The previous prime is 206240911. The next prime is 206240929. The reversal of 206240921 is 129042602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 202777600 + 3463321 = 14240^2 + 1861^2 .

It is a cyclic number.

It is not a de Polignac number, because 206240921 - 2²⁶ = 139132057 is a prime.

It is not a weakly prime, because it can be changed into another prime (206240929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103120460 + 103120461.

It is an arithmetic number, because the mean of its divisors is an integer number (103120461).

Almost surely, 2^206240921 is an apocalyptic number.

It is an amenable number.

206240921 is a deficient number, since it is larger than the sum of its proper divisors (1).

206240921 is an equidigital number, since it uses as much as digits as its factorization.

206240921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 206240921 is about 14361.0905226588. The cubic root of 206240921 is about 590.8242057382.

The spelling of 206240921 in words is "two hundred six million, two hundred forty thousand, nine hundred twenty-one".