261686528 has 36 divisors (see below), whose sum is σ = 523672800. Its totient is φ = 130512384.

The previous prime is 261686527. The next prime is 261686549. The reversal of 261686528 is 825686162.

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 3 ways as a sum of consecutive naturals, for example, 123623 + ... + 125721.

Almost surely, 2^261686528 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261686528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (261836400).

261686528 is an abundant number, since it is smaller than the sum of its proper divisors (261986272).

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

261686528 is an equidigital number, since it uses as much as digits as its factorization.

261686528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2602 (or 2588 counting only the distinct ones).

The product of its digits is 276480, while the sum is 44.

The square root of 261686528 is about 16176.7279757063. The cubic root of 261686528 is about 639.6274915589.

The spelling of 261686528 in words is "two hundred sixty-one million, six hundred eighty-six thousand, five hundred twenty-eight".