205656650643643 has 4 divisors (see below), whose sum is σ = 205910861584680. Its totient is φ = 205402439702608.

The previous prime is 205656650643641. The next prime is 205656650643677. The reversal of 205656650643643 is 346346056656502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 205656650643643 - 2¹ = 205656650643641 is a prime.

It is a super-2 number, since 2×205656650643643² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205656650643641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127105469305 + ... + 127105470922.

It is an arithmetic number, because the mean of its divisors is an integer number (51477715396170).

Almost surely, 2^{205656650643643} is an apocalyptic number.

205656650643643 is a deficient number, since it is larger than the sum of its proper divisors (254210941037).

205656650643643 is an equidigital number, since it uses as much as digits as its factorization.

205656650643643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254210941036.

The product of its (nonzero) digits is 279936000, while the sum is 61.

The spelling of 205656650643643 in words is "two hundred five trillion, six hundred fifty-six billion, six hundred fifty million, six hundred forty-three thousand, six hundred forty-three".