261535 has 8 divisors (see below), whose sum is σ = 330480. Its totient is φ = 198144.

The previous prime is 261529. The next prime is 261557. The reversal of 261535 is 535162.

It is a happy number.

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 261535 - 2⁷ = 261407 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1282 + ... + 1471.

It is an arithmetic number, because the mean of its divisors is an integer number (41310).

2²⁶¹⁵³⁵ is an apocalyptic number.

261535 is a deficient number, since it is larger than the sum of its proper divisors (68945).

261535 is a wasteful number, since it uses less digits than its factorization.

261535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2777.

The product of its digits is 900, while the sum is 22.

The square root of 261535 is about 511.4049276258. The cubic root of 261535 is about 63.9504010246.

Adding to 261535 its reverse (535162), we get a palindrome (796697).

The spelling of 261535 in words is "two hundred sixty-one thousand, five hundred thirty-five".