206640236 has 24 divisors (see below), whose sum is σ = 417702096. Its totient is φ = 88401920.

The previous prime is 206640233. The next prime is 206640271. The reversal of 206640236 is 632046602.

It is a junction number, because it is equal to n+sod(n) for n = 206640199 and 206640208.

It is not an unprimeable number, because it can be changed into a prime (206640233) 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, 137381 + ... + 138876.

It is an arithmetic number, because the mean of its divisors is an integer number (17404254).

Almost surely, 2^206640236 is an apocalyptic number.

It is an amenable number.

206640236 is an abundant number, since it is smaller than the sum of its proper divisors (211061860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

206640236 is a wasteful number, since it uses less digits than its factorization.

206640236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276289 (or 276287 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 29.

The square root of 206640236 is about 14374.9864695588. The cubic root of 206640236 is about 591.2052695728.

Adding to 206640236 its reverse (632046602), we get a palindrome (838686838).

The spelling of 206640236 in words is "two hundred six million, six hundred forty thousand, two hundred thirty-six".