261131273 has 4 divisors (see below), whose sum is σ = 281218308. Its totient is φ = 241044240.

The previous prime is 261131243. The next prime is 261131287. The reversal of 261131273 is 372131162.

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

It can be written as a sum of positive squares in 2 ways, for example, as 26183689 + 234947584 = 5117^2 + 15328^2 .

It is a cyclic number.

It is not a de Polignac number, because 261131273 - 2⁶ = 261131209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261131243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10043498 + ... + 10043523.

It is an arithmetic number, because the mean of its divisors is an integer number (70304577).

Almost surely, 2^261131273 is an apocalyptic number.

It is an amenable number.

261131273 is a deficient number, since it is larger than the sum of its proper divisors (20087035).

261131273 is a wasteful number, since it uses less digits than its factorization.

261131273 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20087034.

The product of its digits is 1512, while the sum is 26.

The square root of 261131273 is about 16159.5567080288. The cubic root of 261131273 is about 639.1747770635.

The spelling of 261131273 in words is "two hundred sixty-one million, one hundred thirty-one thousand, two hundred seventy-three".