206471721 has 8 divisors (see below), whose sum is σ = 275575744. Its totient is φ = 137507760.

The previous prime is 206471719. The next prime is 206471731. The reversal of 206471721 is 127174602.

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

It is not a de Polignac number, because 206471721 - 2¹ = 206471719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206471701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31525 + ... + 37506.

It is an arithmetic number, because the mean of its divisors is an integer number (34446968).

Almost surely, 2^206471721 is an apocalyptic number.

It is an amenable number.

206471721 is a deficient number, since it is larger than the sum of its proper divisors (69104023).

206471721 is an equidigital number, since it uses as much as digits as its factorization.

206471721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70031.

The product of its (nonzero) digits is 4704, while the sum is 30.

The square root of 206471721 is about 14369.1238772585. The cubic root of 206471721 is about 591.0445166750.

The spelling of 206471721 in words is "two hundred six million, four hundred seventy-one thousand, seven hundred twenty-one".