261685481 has 8 divisors (see below), whose sum is σ = 267318144. Its totient is φ = 256107040.

The previous prime is 261685447. The next prime is 261685483. The reversal of 261685481 is 184586162.

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 261685481 - 2¹⁰ = 261684457 is a prime.

It is a super-2 number, since 2×261685481² = 136958581932402722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (261685483) 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 7 ways as a sum of consecutive naturals, for example, 3725 + ... + 23178.

It is an arithmetic number, because the mean of its divisors is an integer number (33414768).

Almost surely, 2^261685481 is an apocalyptic number.

It is an amenable number.

261685481 is a deficient number, since it is larger than the sum of its proper divisors (5632663).

261685481 is a wasteful number, since it uses less digits than its factorization.

261685481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27111.

The product of its digits is 92160, while the sum is 41.

The square root of 261685481 is about 16176.6956143707. The cubic root of 261685481 is about 639.6266385143.

The spelling of 261685481 in words is "two hundred sixty-one million, six hundred eighty-five thousand, four hundred eighty-one".