261686526 has 16 divisors (see below), whose sum is σ = 526032144. Its totient is φ = 86785664.

The previous prime is 261686507. The next prime is 261686527. The reversal of 261686526 is 625686162.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261686527) 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, 109515 + ... + 111878.

It is an arithmetic number, because the mean of its divisors is an integer number (32877009).

Almost surely, 2^261686526 is an apocalyptic number.

261686526 is an abundant number, since it is smaller than the sum of its proper divisors (264345618).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261686526 is a wasteful number, since it uses less digits than its factorization.

261686526 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221595.

The product of its digits is 207360, while the sum is 42.

The square root of 261686526 is about 16176.7279138891. The cubic root of 261686526 is about 639.6274899294.

The spelling of 261686526 in words is "two hundred sixty-one million, six hundred eighty-six thousand, five hundred twenty-six".