205655643 has 24 divisors (see below), whose sum is σ = 308904960. Its totient is φ = 131701680.

The previous prime is 205655561. The next prime is 205655693. The reversal of 205655643 is 346556502.

It is a happy number.

205655643 is a `hidden beast` number, since 2 + 0 + 5 + 6 + 5 + 5 + 643 = 666.

It is not a de Polignac number, because 205655643 - 2²⁵ = 172101211 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 205655598 and 205655607.

It is not an unprimeable number, because it can be changed into a prime (205655693) 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, 36130 + ... + 41432.

It is an arithmetic number, because the mean of its divisors is an integer number (12871040).

Almost surely, 2^205655643 is an apocalyptic number.

205655643 is a deficient number, since it is larger than the sum of its proper divisors (103249317).

205655643 is a wasteful number, since it uses less digits than its factorization.

205655643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5479 (or 5476 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 36.

The square root of 205655643 is about 14340.6988323443. The cubic root of 205655643 is about 590.2647887401.

The spelling of 205655643 in words is "two hundred five million, six hundred fifty-five thousand, six hundred forty-three".