206642129 has 4 divisors (see below), whose sum is σ = 207113280. Its totient is φ = 206170980.

The previous prime is 206642113. The next prime is 206642153. The reversal of 206642129 is 921246602.

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, and also an emirpimes, since its reverse is a distinct semiprime: 921246602 = 2 ⋅460623301.

It is a cyclic number.

It is not a de Polignac number, because 206642129 - 2⁴ = 206642113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 206642095 and 206642104.

It is not an unprimeable number, because it can be changed into a prime (206642159) 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, 234917 + ... + 235794.

It is an arithmetic number, because the mean of its divisors is an integer number (51778320).

Almost surely, 2^206642129 is an apocalyptic number.

It is an amenable number.

206642129 is a deficient number, since it is larger than the sum of its proper divisors (471151).

206642129 is an equidigital number, since it uses as much as digits as its factorization.

206642129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471150.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 206642129 is about 14375.0523129483. The cubic root of 206642129 is about 591.2070748813.

The spelling of 206642129 in words is "two hundred six million, six hundred forty-two thousand, one hundred twenty-nine".