261686543 has 8 divisors (see below), whose sum is σ = 264579840. Its totient is φ = 258807960.

The previous prime is 261686527. The next prime is 261686549. The reversal of 261686543 is 345686162.

261686543 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 261686543 - 2⁴ = 261686527 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261686543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261686549) 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, 34196 + ... + 41142.

It is an arithmetic number, because the mean of its divisors is an integer number (33072480).

Almost surely, 2^261686543 is an apocalyptic number.

261686543 is a deficient number, since it is larger than the sum of its proper divisors (2893297).

261686543 is a wasteful number, since it uses less digits than its factorization.

261686543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7357.

The product of its digits is 207360, while the sum is 41.

The square root of 261686543 is about 16176.7284393353. The cubic root of 261686543 is about 639.6275037802.

The spelling of 261686543 in words is "two hundred sixty-one million, six hundred eighty-six thousand, five hundred forty-three".