261157273 has 8 divisors (see below), whose sum is σ = 281372616. Its totient is φ = 240960000.

The previous prime is 261157243. The next prime is 261157289. The reversal of 261157273 is 372751162.

It can be written as a sum of positive squares in 4 ways, for example, as 5253264 + 255904009 = 2292^2 + 15997^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261157273 - 2²¹ = 259060121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261157243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49503 + ... + 54523.

It is an arithmetic number, because the mean of its divisors is an integer number (35171577).

Almost surely, 2^261157273 is an apocalyptic number.

It is an amenable number.

261157273 is a deficient number, since it is larger than the sum of its proper divisors (20215343).

261157273 is a wasteful number, since it uses less digits than its factorization.

261157273 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9035.

The product of its digits is 17640, while the sum is 34.

The square root of 261157273 is about 16160.3611655185. The cubic root of 261157273 is about 639.1959898843.

The spelling of 261157273 in words is "two hundred sixty-one million, one hundred fifty-seven thousand, two hundred seventy-three".