206196021 has 6 divisors (see below), whose sum is σ = 297838710. Its totient is φ = 137464008.

The previous prime is 206196017. The next prime is 206196049. The reversal of 206196021 is 120691602.

206196021 is a `hidden beast` number, since 20 + 619 + 6 + 0 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 178222500 + 27973521 = 13350^2 + 5289^2 .

It is not a de Polignac number, because 206196021 - 2² = 206196017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206196071) 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 in 5 ways as a sum of consecutive naturals, for example, 11455326 + ... + 11455343.

It is an arithmetic number, because the mean of its divisors is an integer number (49639785).

Almost surely, 2^206196021 is an apocalyptic number.

It is an amenable number.

206196021 is a deficient number, since it is larger than the sum of its proper divisors (91642689).

206196021 is a wasteful number, since it uses less digits than its factorization.

206196021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22910675 (or 22910672 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 206196021 is about 14359.5271858094. The cubic root of 206196021 is about 590.7813271926.

The spelling of 206196021 in words is "two hundred six million, one hundred ninety-six thousand, twenty-one".