205666613025 has 24 divisors (see below), whose sum is σ = 340183018560. Its totient is φ = 109641263040.

The previous prime is 205666612993. The next prime is 205666613029. The reversal of 205666613025 is 520316666502.

It is not a de Polignac number, because 205666613025 - 2⁵ = 205666612993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (205666613029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 420637 + ... + 766986.

It is an arithmetic number, because the mean of its divisors is an integer number (14174292440).

Almost surely, 2^205666613025 is an apocalyptic number.

205666613025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

205666613025 is a deficient number, since it is larger than the sum of its proper divisors (134516405535).

205666613025 is a wasteful number, since it uses less digits than its factorization.

205666613025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1189945 (or 1189940 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 42.

The spelling of 205666613025 in words is "two hundred five billion, six hundred sixty-six million, six hundred thirteen thousand, twenty-five".