205615001117 has 2 divisors, whose sum is σ = 205615001118. Its totient is φ = 205615001116.

The previous prime is 205615001083. The next prime is 205615001131. The reversal of 205615001117 is 711100516502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 204092518756 + 1522482361 = 451766^2 + 39019^2 .

It is a cyclic number.

It is not a de Polignac number, because 205615001117 - 2³² = 201320033821 is a prime.

It is a super-2 number, since 2×205615001117² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 205615001117.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205615001197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102807500558 + 102807500559.

It is an arithmetic number, because the mean of its divisors is an integer number (102807500559).

Almost surely, 2^205615001117 is an apocalyptic number.

It is an amenable number.

205615001117 is a deficient number, since it is larger than the sum of its proper divisors (1).

205615001117 is an equidigital number, since it uses as much as digits as its factorization.

205615001117 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2100, while the sum is 29.

Adding to 205615001117 its reverse (711100516502), we get a palindrome (916715517619).

The spelling of 205615001117 in words is "two hundred five billion, six hundred fifteen million, one thousand, one hundred seventeen".