205685240 has 16 divisors (see below), whose sum is σ = 462791880. Its totient is φ = 82274080.

The previous prime is 205685239. The next prime is 205685339. The reversal of 205685240 is 42586502.

It is a junction number, because it is equal to n+sod(n) for n = 205685197 and 205685206.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2571026 + ... + 2571105.

Almost surely, 2^205685240 is an apocalyptic number.

205685240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205685240 is an abundant number, since it is smaller than the sum of its proper divisors (257106640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

205685240 is a wasteful number, since it uses less digits than its factorization.

205685240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5142142 (or 5142138 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 32.

The square root of 205685240 is about 14341.7307184314. The cubic root of 205685240 is about 590.2931034327.

The spelling of 205685240 in words is "two hundred five million, six hundred eighty-five thousand, two hundred forty".