206420399 has 2 divisors, whose sum is σ = 206420400. Its totient is φ = 206420398.

The previous prime is 206420393. The next prime is 206420411. The reversal of 206420399 is 993024602.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-206420399 is a prime.

It is a super-2 number, since 2×206420399² = 85218762246638402, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206420393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103210199 + 103210200.

It is an arithmetic number, because the mean of its divisors is an integer number (103210200).

Almost surely, 2^206420399 is an apocalyptic number.

206420399 is a deficient number, since it is larger than the sum of its proper divisors (1).

206420399 is an equidigital number, since it uses as much as digits as its factorization.

206420399 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 35.

The square root of 206420399 is about 14367.3379232202. The cubic root of 206420399 is about 590.9955412831.

The spelling of 206420399 in words is "two hundred six million, four hundred twenty thousand, three hundred ninety-nine".