205216440 has 128 divisors (see below), whose sum is σ = 723340800. Its totient is φ = 45918720.

The previous prime is 205216433. The next prime is 205216457. The reversal of 205216440 is 44612502.

It is a super-2 number, since 2×205216440² = 84227574492547200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 205216440.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11181 + ... + 23139.

It is an arithmetic number, because the mean of its divisors is an integer number (5651100).

Almost surely, 2^205216440 is an apocalyptic number.

205216440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 205216440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (361670400).

205216440 is an abundant number, since it is smaller than the sum of its proper divisors (518124360).

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

205216440 is a wasteful number, since it uses less digits than its factorization.

205216440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11997 (or 11993 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 205216440 is about 14325.3774819374. The cubic root of 205216440 is about 589.8442948307.

Adding to 205216440 its reverse (44612502), we get a palindrome (249828942).

The spelling of 205216440 in words is "two hundred five million, two hundred sixteen thousand, four hundred forty".