205132140021 has 4 divisors (see below), whose sum is σ = 273509520032. Its totient is φ = 136754760012.

The previous prime is 205132140019. The next prime is 205132140043. The reversal of 205132140021 is 120041231502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 205132140021 - 2¹ = 205132140019 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 205132140021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205132640021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34188690001 + ... + 34188690006.

It is an arithmetic number, because the mean of its divisors is an integer number (68377380008).

Almost surely, 2^205132140021 is an apocalyptic number.

It is an amenable number.

205132140021 is a deficient number, since it is larger than the sum of its proper divisors (68377380011).

205132140021 is an equidigital number, since it uses as much as digits as its factorization.

205132140021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68377380010.

The product of its (nonzero) digits is 480, while the sum is 21.

Adding to 205132140021 its reverse (120041231502), we get a palindrome (325173371523).

The spelling of 205132140021 in words is "two hundred five billion, one hundred thirty-two million, one hundred forty thousand, twenty-one".