206642331 has 12 divisors (see below), whose sum is σ = 341123952. Its totient is φ = 118081296.

The previous prime is 206642297. The next prime is 206642351. The reversal of 206642331 is 133246602.

206642331 is a `hidden beast` number, since 206 + 6 + 423 + 31 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-206642331 is a prime.

It is a super-2 number, since 2×206642331² = 85402105922227122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 206642295 and 206642304.

It is not an unprimeable number, because it can be changed into a prime (206642351) 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 11 ways as a sum of consecutive naturals, for example, 1639956 + ... + 1640081.

It is an arithmetic number, because the mean of its divisors is an integer number (28426996).

Almost surely, 2^206642331 is an apocalyptic number.

206642331 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

206642331 is a deficient number, since it is larger than the sum of its proper divisors (134481621).

206642331 is a wasteful number, since it uses less digits than its factorization.

206642331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3280050 (or 3280047 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 27.

The square root of 206642331 is about 14375.0593390080. The cubic root of 206642331 is about 591.2072675232.

Adding to 206642331 its reverse (133246602), we get a palindrome (339888933).

The spelling of 206642331 in words is "two hundred six million, six hundred forty-two thousand, three hundred thirty-one".