205991384511 has 16 divisors (see below), whose sum is σ = 299813184000. Its totient is φ = 124764366720.

The previous prime is 205991384507. The next prime is 205991384513. The reversal of 205991384511 is 115483199502.

It is not a de Polignac number, because 205991384511 - 2² = 205991384507 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205991384513) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1919386 + ... + 2023863.

It is an arithmetic number, because the mean of its divisors is an integer number (18738324000).

Almost surely, 2^205991384511 is an apocalyptic number.

205991384511 is a deficient number, since it is larger than the sum of its proper divisors (93821799489).

205991384511 is a wasteful number, since it uses less digits than its factorization.

205991384511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3944846.

The product of its (nonzero) digits is 388800, while the sum is 48.

The spelling of 205991384511 in words is "two hundred five billion, nine hundred ninety-one million, three hundred eighty-four thousand, five hundred eleven".