205661423 has 16 divisors (see below), whose sum is σ = 235097856. Its totient is φ = 178083840.

The previous prime is 205661381. The next prime is 205661441. The reversal of 205661423 is 324166502.

It is not a de Polignac number, because 205661423 - 2⁸ = 205661167 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205661473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 63440 + ... + 66602.

It is an arithmetic number, because the mean of its divisors is an integer number (14693616).

Almost surely, 2^205661423 is an apocalyptic number.

205661423 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

205661423 is a deficient number, since it is larger than the sum of its proper divisors (29436433).

205661423 is a wasteful number, since it uses less digits than its factorization.

205661423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3454.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 205661423 is about 14340.9003552776. The cubic root of 205661423 is about 590.2703185317.

The spelling of 205661423 in words is "two hundred five million, six hundred sixty-one thousand, four hundred twenty-three".