206774221 has 4 divisors (see below), whose sum is σ = 208906012. Its totient is φ = 204642432.

The previous prime is 206774203. The next prime is 206774231. The reversal of 206774221 is 122477602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 164198596 + 42575625 = 12814^2 + 6525^2 .

It is a cyclic number.

It is not a de Polignac number, because 206774221 - 2⁵ = 206774189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206774231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1065750 + ... + 1065943.

It is an arithmetic number, because the mean of its divisors is an integer number (52226503).

Almost surely, 2^206774221 is an apocalyptic number.

It is an amenable number.

206774221 is a deficient number, since it is larger than the sum of its proper divisors (2131791).

206774221 is an equidigital number, since it uses as much as digits as its factorization.

206774221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2131790.

The product of its (nonzero) digits is 9408, while the sum is 31.

The square root of 206774221 is about 14379.6460665762. The cubic root of 206774221 is about 591.3330206267. Note that the first 3 decimals are identical.

The spelling of 206774221 in words is "two hundred six million, seven hundred seventy-four thousand, two hundred twenty-one".