205535640 has 64 divisors (see below), whose sum is σ = 617621760. Its totient is φ = 54719360.

The previous prime is 205535633. The next prime is 205535641. The reversal of 205535640 is 46535502.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 205535598 and 205535607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205535641) 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, 105475 + ... + 107405.

It is an arithmetic number, because the mean of its divisors is an integer number (9650340).

Almost surely, 2^205535640 is an apocalyptic number.

205535640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205535640 is an abundant number, since it is smaller than the sum of its proper divisors (412086120).

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

205535640 is a wasteful number, since it uses less digits than its factorization.

205535640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2832 (or 2828 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 30.

The square root of 205535640 is about 14336.5142206884. The cubic root of 205535640 is about 590.1499570951.

The spelling of 205535640 in words is "two hundred five million, five hundred thirty-five thousand, six hundred forty".