261163111 has 4 divisors (see below), whose sum is σ = 284905224. Its totient is φ = 237421000.

The previous prime is 261163109. The next prime is 261163141. The reversal of 261163111 is 111361162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261163111 - 2¹ = 261163109 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261163141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11871040 + ... + 11871061.

It is an arithmetic number, because the mean of its divisors is an integer number (71226306).

Almost surely, 2^261163111 is an apocalyptic number.

261163111 is a deficient number, since it is larger than the sum of its proper divisors (23742113).

261163111 is a wasteful number, since it uses less digits than its factorization.

261163111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23742112.

The product of its digits is 216, while the sum is 22.

The square root of 261163111 is about 16160.5417916603. The cubic root of 261163111 is about 639.2007527848.

The spelling of 261163111 in words is "two hundred sixty-one million, one hundred sixty-three thousand, one hundred eleven".