261293281 has 12 divisors (see below), whose sum is σ = 279173520. Its totient is φ = 244500800.

The previous prime is 261293267. The next prime is 261293293. The reversal of 261293281 is 182392162.

It is not a de Polignac number, because 261293281 - 2¹⁵ = 261260513 is a prime.

It is a super-2 number, since 2×261293281² = 136548357391489922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261293381) 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 11 ways as a sum of consecutive naturals, for example, 49206 + ... + 54256.

It is an arithmetic number, because the mean of its divisors is an integer number (23264460).

Almost surely, 2^261293281 is an apocalyptic number.

It is an amenable number.

261293281 is a deficient number, since it is larger than the sum of its proper divisors (17880239).

261293281 is a wasteful number, since it uses less digits than its factorization.

261293281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5264 (or 5247 counting only the distinct ones).

The product of its digits is 10368, while the sum is 34.

The square root of 261293281 is about 16164.5686920499. The cubic root of 261293281 is about 639.3069328419.

The spelling of 261293281 in words is "two hundred sixty-one million, two hundred ninety-three thousand, two hundred eighty-one".