206676721 has 4 divisors (see below), whose sum is σ = 213343744. Its totient is φ = 200009700.

The previous prime is 206676713. The next prime is 206676727. The reversal of 206676721 is 127676602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 206676721 - 2³ = 206676713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206676727) 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 3 ways as a sum of consecutive naturals, for example, 3333465 + ... + 3333526.

It is an arithmetic number, because the mean of its divisors is an integer number (53335936).

Almost surely, 2^206676721 is an apocalyptic number.

It is an amenable number.

206676721 is a deficient number, since it is larger than the sum of its proper divisors (6667023).

206676721 is an equidigital number, since it uses as much as digits as its factorization.

206676721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6667022.

The product of its (nonzero) digits is 42336, while the sum is 37.

The square root of 206676721 is about 14376.2554582200. The cubic root of 206676721 is about 591.2400624981.

It can be divided in two parts, 2066 and 76721, that added together give a palindrome (78787).

The spelling of 206676721 in words is "two hundred six million, six hundred seventy-six thousand, seven hundred twenty-one".