206434421 has 2 divisors, whose sum is σ = 206434422. Its totient is φ = 206434420.

The previous prime is 206434409. The next prime is 206434427. The reversal of 206434421 is 124434602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 187416100 + 19018321 = 13690^2 + 4361^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-206434421 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206434427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103217210 + 103217211.

It is an arithmetic number, because the mean of its divisors is an integer number (103217211).

Almost surely, 2^206434421 is an apocalyptic number.

It is an amenable number.

206434421 is a deficient number, since it is larger than the sum of its proper divisors (1).

206434421 is an equidigital number, since it uses as much as digits as its factorization.

206434421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4608, while the sum is 26.

The square root of 206434421 is about 14367.8258967737. The cubic root of 206434421 is about 591.0089229578.

The spelling of 206434421 in words is "two hundred six million, four hundred thirty-four thousand, four hundred twenty-one".