206820401 has 2 divisors, whose sum is σ = 206820402. Its totient is φ = 206820400.

The previous prime is 206820391. The next prime is 206820403. The reversal of 206820401 is 104028602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 206640625 + 179776 = 14375^2 + 424^2 .

It is a cyclic number.

It is not a de Polignac number, because 206820401 - 2¹⁰ = 206819377 is a prime.

Together with 206820403, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (206820403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103410200 + 103410201.

It is an arithmetic number, because the mean of its divisors is an integer number (103410201).

Almost surely, 2^206820401 is an apocalyptic number.

It is an amenable number.

206820401 is a deficient number, since it is larger than the sum of its proper divisors (1).

206820401 is an equidigital number, since it uses as much as digits as its factorization.

206820401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 206820401 is about 14381.2517188178. The cubic root of 206820401 is about 591.3770392122.

The spelling of 206820401 in words is "two hundred six million, eight hundred twenty thousand, four hundred one".