261886261 has 8 divisors (see below), whose sum is σ = 322321664. Its totient is φ = 207206640.

The previous prime is 261886243. The next prime is 261886271. The reversal of 261886261 is 162688162.

261886261 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 261886261 - 2⁷ = 261886133 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261886271) 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, 1438845 + ... + 1439026.

It is an arithmetic number, because the mean of its divisors is an integer number (40290208).

Almost surely, 2^261886261 is an apocalyptic number.

It is an amenable number.

261886261 is a deficient number, since it is larger than the sum of its proper divisors (60435403).

261886261 is a wasteful number, since it uses less digits than its factorization.

261886261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2877891.

The product of its digits is 55296, while the sum is 40.

The square root of 261886261 is about 16182.9002654036. The cubic root of 261886261 is about 639.7901826859.

The spelling of 261886261 in words is "two hundred sixty-one million, eight hundred eighty-six thousand, two hundred sixty-one".