206516720221 has 8 divisors (see below), whose sum is σ = 239006693120. Its totient is φ = 174773643408.

The previous prime is 206516720219. The next prime is 206516720227. The reversal of 206516720221 is 122027615602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 206516720221 - 2¹ = 206516720219 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 (206516720227) 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 in 7 ways as a sum of consecutive naturals, for example, 186723426 + ... + 186724531.

It is an arithmetic number, because the mean of its divisors is an integer number (29875836640).

Almost surely, 2^206516720221 is an apocalyptic number.

It is an amenable number.

206516720221 is a deficient number, since it is larger than the sum of its proper divisors (32489972899).

206516720221 is an equidigital number, since it uses as much as digits as its factorization.

206516720221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373448043.

The product of its (nonzero) digits is 20160, while the sum is 34.

The spelling of 206516720221 in words is "two hundred six billion, five hundred sixteen million, seven hundred twenty thousand, two hundred twenty-one".