206642121 has 8 divisors (see below), whose sum is σ = 314883264. Its totient is φ = 118081200.

The previous prime is 206642113. The next prime is 206642153. The reversal of 206642121 is 121246602.

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

It is not a de Polignac number, because 206642121 - 2³ = 206642113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 206642091 and 206642100.

It is not an unprimeable number, because it can be changed into a prime (206642171) 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 7 ways as a sum of consecutive naturals, for example, 4920030 + ... + 4920071.

It is an arithmetic number, because the mean of its divisors is an integer number (39360408).

Almost surely, 2^206642121 is an apocalyptic number.

206642121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

206642121 is a deficient number, since it is larger than the sum of its proper divisors (108241143).

206642121 is an equidigital number, since it uses as much as digits as its factorization.

206642121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9840111.

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 206642121 is about 14375.0520346884. The cubic root of 206642121 is about 591.2070672519.

Adding to 206642121 its reverse (121246602), we get a palindrome (327888723).

The spelling of 206642121 in words is "two hundred six million, six hundred forty-two thousand, one hundred twenty-one".