205002640 has 20 divisors (see below), whose sum is σ = 476631324. Its totient is φ = 82001024.

The previous prime is 205002601. The next prime is 205002641. The reversal of 205002640 is 46200502.

It can be written as a sum of positive squares in 2 ways, for example, as 137170944 + 67831696 = 11712^2 + 8236^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (205002641) by changing a digit.

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, 1281187 + ... + 1281346.

Almost surely, 2^205002640 is an apocalyptic number.

205002640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205002640 is an abundant number, since it is smaller than the sum of its proper divisors (271628684).

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

205002640 is a wasteful number, since it uses less digits than its factorization.

205002640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2562546 (or 2562540 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 205002640 is about 14317.9132557786. The cubic root of 205002640 is about 589.6393851102.

The spelling of 205002640 in words is "two hundred five million, two thousand, six hundred forty".