205215340 has 48 divisors (see below), whose sum is σ = 471129120. Its totient is φ = 74465280.

The previous prime is 205215331. The next prime is 205215343. The reversal of 205215340 is 43512502.

It is a super-2 number, since 2×205215340² = 84226671542631200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (205215343) 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, 168574 + ... + 169786.

It is an arithmetic number, because the mean of its divisors is an integer number (9815190).

Almost surely, 2^205215340 is an apocalyptic number.

205215340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205215340 is an abundant number, since it is smaller than the sum of its proper divisors (265913780).

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

205215340 is a wasteful number, since it uses less digits than its factorization.

205215340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2002 (or 2000 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 205215340 is about 14325.3390884823. The cubic root of 205215340 is about 589.8432409355.

Adding to 205215340 its reverse (43512502), we get a palindrome (248727842).

The spelling of 205215340 in words is "two hundred five million, two hundred fifteen thousand, three hundred forty".