205031153221261 has 4 divisors (see below), whose sum is σ = 205035117602400. Its totient is φ = 205027188840124.

The previous prime is 205031153221259. The next prime is 205031153221291. The reversal of 205031153221261 is 162122351130502.

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 a cyclic number.

It is not a de Polignac number, because 205031153221261 - 2¹ = 205031153221259 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205031153221231) 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, 1982112991 + ... + 1982216428.

It is an arithmetic number, because the mean of its divisors is an integer number (51258779400600).

Almost surely, 2^{205031153221261} is an apocalyptic number.

It is an amenable number.

205031153221261 is a deficient number, since it is larger than the sum of its proper divisors (3964381139).

205031153221261 is an equidigital number, since it uses as much as digits as its factorization.

205031153221261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3964381138.

The product of its (nonzero) digits is 21600, while the sum is 34.

The spelling of 205031153221261 in words is "two hundred five trillion, thirty-one billion, one hundred fifty-three million, two hundred twenty-one thousand, two hundred sixty-one".