205404120251013 has 4 divisors (see below), whose sum is σ = 273872160334688. Its totient is φ = 136936080167340.

The previous prime is 205404120250999. The next prime is 205404120251023. The reversal of 205404120251013 is 310152021404502.

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 205404120251013 - 2⁶ = 205404120250949 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 (205404120251023) 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, 34234020041833 + ... + 34234020041838.

It is an arithmetic number, because the mean of its divisors is an integer number (68468040083672).

Almost surely, 2^{205404120251013} is an apocalyptic number.

It is an amenable number.

205404120251013 is a deficient number, since it is larger than the sum of its proper divisors (68468040083675).

205404120251013 is an equidigital number, since it uses as much as digits as its factorization.

205404120251013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68468040083674.

The product of its (nonzero) digits is 9600, while the sum is 30.

Adding to 205404120251013 its reverse (310152021404502), we get a palindrome (515556141655515).

The spelling of 205404120251013 in words is "two hundred five trillion, four hundred four billion, one hundred twenty million, two hundred fifty-one thousand, thirteen".