261216113 has 4 divisors (see below), whose sum is σ = 261652800. Its totient is φ = 260779428.

The previous prime is 261216103. The next prime is 261216127. The reversal of 261216113 is 311612162.

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 261216113 - 2⁴ = 261216097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261216103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 217445 + ... + 218642.

It is an arithmetic number, because the mean of its divisors is an integer number (65413200).

Almost surely, 2^261216113 is an apocalyptic number.

It is an amenable number.

261216113 is a deficient number, since it is larger than the sum of its proper divisors (436687).

261216113 is an equidigital number, since it uses as much as digits as its factorization.

261216113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 436686.

The product of its digits is 432, while the sum is 23.

The square root of 261216113 is about 16162.1815668554. The cubic root of 261216113 is about 639.2439909315.

Adding to 261216113 its reverse (311612162), we get a palindrome (572828275).

The spelling of 261216113 in words is "two hundred sixty-one million, two hundred sixteen thousand, one hundred thirteen".