205131530155105 has 16 divisors (see below), whose sum is σ = 247731497289360. Its totient is φ = 163056165472512.

The previous prime is 205131530155081. The next prime is 205131530155109. The reversal of 205131530155105 is 501551035131502.

It can be written as a sum of positive squares in 8 ways, for example, as 15839500532769 + 189292029622336 = 3979887^2 + 13758344^2 .

It is a cyclic number.

It is not a de Polignac number, because 205131530155105 - 2⁷ = 205131530154977 is a prime.

It is a super-2 number, since 2×205131530155105² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (205131530155109) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30878127 + ... + 36928603.

It is an arithmetic number, because the mean of its divisors is an integer number (15483218580585).

Almost surely, 2^{205131530155105} is an apocalyptic number.

It is an amenable number.

205131530155105 is a deficient number, since it is larger than the sum of its proper divisors (42599967134255).

205131530155105 is a wasteful number, since it uses less digits than its factorization.

205131530155105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6093828.

The product of its (nonzero) digits is 56250, while the sum is 37.

Adding to 205131530155105 its reverse (501551035131502), we get a palindrome (706682565286607).

The spelling of 205131530155105 in words is "two hundred five trillion, one hundred thirty-one billion, five hundred thirty million, one hundred fifty-five thousand, one hundred five".