261106315517 has 4 divisors (see below), whose sum is σ = 261119929056. Its totient is φ = 261092701980.

The previous prime is 261106315513. The next prime is 261106315637. The reversal of 261106315517 is 715513601162.

It is a happy number.

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 261106315517 - 2² = 261106315513 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 (261106315513) 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, 6777959 + ... + 6816372.

It is an arithmetic number, because the mean of its divisors is an integer number (65279982264).

Almost surely, 2^261106315517 is an apocalyptic number.

It is an amenable number.

261106315517 is a deficient number, since it is larger than the sum of its proper divisors (13613539).

261106315517 is a wasteful number, since it uses less digits than its factorization.

261106315517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13613538.

The product of its (nonzero) digits is 37800, while the sum is 38.

Adding to 261106315517 its reverse (715513601162), we get a palindrome (976619916679).

The spelling of 261106315517 in words is "two hundred sixty-one billion, one hundred six million, three hundred fifteen thousand, five hundred seventeen".