206556813 has 24 divisors (see below), whose sum is σ = 321384960. Its totient is φ = 127464480.

The previous prime is 206556793. The next prime is 206556841. The reversal of 206556813 is 318655602.

206556813 is a `hidden beast` number, since 20 + 6 + 556 + 81 + 3 = 666.

It is not a de Polignac number, because 206556813 - 2⁸ = 206556557 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206556013) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9678 + ... + 22511.

It is an arithmetic number, because the mean of its divisors is an integer number (13391040).

Almost surely, 2^206556813 is an apocalyptic number.

206556813 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

206556813 is a deficient number, since it is larger than the sum of its proper divisors (114828147).

206556813 is a wasteful number, since it uses less digits than its factorization.

206556813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32249 (or 32246 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 206556813 is about 14372.0845043438. The cubic root of 206556813 is about 591.1257001132.

The spelling of 206556813 in words is "two hundred six million, five hundred fifty-six thousand, eight hundred thirteen".