261533 has 8 divisors (see below), whose sum is σ = 278208. Its totient is φ = 245344.

The previous prime is 261529. The next prime is 261557. The reversal of 261533 is 335162.

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 261533 - 2² = 261529 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261523) 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, 1841 + ... + 1977.

It is an arithmetic number, because the mean of its divisors is an integer number (34776).

2²⁶¹⁵³³ is an apocalyptic number.

261533 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

261533 is a deficient number, since it is larger than the sum of its proper divisors (16675).

261533 is a wasteful number, since it uses less digits than its factorization.

261533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243.

The product of its digits is 540, while the sum is 20.

The square root of 261533 is about 511.4029722244. The cubic root of 261533 is about 63.9502380112.

Adding to 261533 its reverse (335162), we get a palindrome (596695).

The spelling of 261533 in words is "two hundred sixty-one thousand, five hundred thirty-three".