206621641 has 2 divisors, whose sum is σ = 206621642. Its totient is φ = 206621640.

The previous prime is 206621593. The next prime is 206621647. The reversal of 206621641 is 146126602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 148937616 + 57684025 = 12204^2 + 7595^2 .

It is a cyclic number.

It is not a de Polignac number, because 206621641 - 2¹⁷ = 206490569 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (206621647) 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, 103310820 + 103310821.

It is an arithmetic number, because the mean of its divisors is an integer number (103310821).

Almost surely, 2^206621641 is an apocalyptic number.

It is an amenable number.

206621641 is a deficient number, since it is larger than the sum of its proper divisors (1).

206621641 is an equidigital number, since it uses as much as digits as its factorization.

206621641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 206621641 is about 14374.3396717901. The cubic root of 206621641 is about 591.1875353825.

The spelling of 206621641 in words is "two hundred six million, six hundred twenty-one thousand, six hundred forty-one".