205540040 has 32 divisors (see below), whose sum is σ = 463337280. Its totient is φ = 82060992.

The previous prime is 205540019. The next prime is 205540057. The reversal of 205540040 is 40045502.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 205539994 and 205540021.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17957 + ... + 27083.

It is an arithmetic number, because the mean of its divisors is an integer number (14479290).

Almost surely, 2^205540040 is an apocalyptic number.

205540040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205540040 is an abundant number, since it is smaller than the sum of its proper divisors (257797240).

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

205540040 is a wasteful number, since it uses less digits than its factorization.

205540040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9701 (or 9697 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 20.

The square root of 205540040 is about 14336.6676741843. The cubic root of 205540040 is about 590.1541682727.

Adding to 205540040 its reverse (40045502), we get a palindrome (245585542).

The spelling of 205540040 in words is "two hundred five million, five hundred forty thousand, forty".