205021154340 has 72 divisors (see below), whose sum is σ = 635129389440. Its totient is φ = 53509065024.

The previous prime is 205021154297. The next prime is 205021154341. The reversal of 205021154340 is 43451120502.

205021154340 is a `hidden beast` number, since 2 + 0 + 502 + 1 + 154 + 3 + 4 + 0 = 666.

205021154340 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×205021154340² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (205021154341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12108630 + ... + 12125549.

It is an arithmetic number, because the mean of its divisors is an integer number (8821241520).

Almost surely, 2^205021154340 is an apocalyptic number.

205021154340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205021154340 is an abundant number, since it is smaller than the sum of its proper divisors (430108235100).

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

205021154340 is a wasteful number, since it uses less digits than its factorization.

205021154340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24234241 (or 24234236 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

Adding to 205021154340 its reverse (43451120502), we get a palindrome (248472274842).

The spelling of 205021154340 in words is "two hundred five billion, twenty-one million, one hundred fifty-four thousand, three hundred forty".