205891132094649 has 31 divisors (see below), whose sum is σ = 308836698141973. Its totient is φ = 137260754729766.

The previous prime is 205891132094623. The next prime is 205891132094653. The reversal of 205891132094649 is 946490231198502.

The square root of 205891132094649 is 14348907.

The cubic root of 205891132094649 is 59049.

It is a perfect power (a square, a cube, a 5-th power, a 6-th power, a 10-th power, a 15-th power, a 30-th power), and thus also a powerful number.

205891132094649 is a `hidden beast` number, since 2 + 0 + 58 + 9 + 113 + 2 + 0 + 9 + 464 + 9 = 666.

It is an ABA number since it can be written as A⋅B^A, here for A=27, B=3.

It is not a de Polignac number, because 205891132094649 - 2¹¹ = 205891132092601 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 3 and base 9.

It is not an unprimeable number, because it can be changed into a prime (205891132094149) by changing a digit.

It is a polite number, since it can be written in 30 ways as a sum of consecutive naturals, for example, 68630377364882 + 68630377364883 + 68630377364884.

Almost surely, 2^{205891132094649} is an apocalyptic number.

205891132094649 is the 14348907-th square number.

205891132094649 is the 7174454-th centered octagonal number.

It is an amenable number.

205891132094649 is a deficient number, since it is larger than the sum of its proper divisors (102945566047324).

205891132094649 is an frugal number, since it uses more digits than its factorization.

205891132094649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90 (or 3 counting only the distinct ones).

The product of its (nonzero) digits is 33592320, while the sum is 63.

The spelling of 205891132094649 in words is "two hundred five trillion, eight hundred ninety-one billion, one hundred thirty-two million, ninety-four thousand, six hundred forty-nine".