261355 has 8 divisors (see below), whose sum is σ = 316512. Its totient is φ = 207168.

The previous prime is 261353. The next prime is 261379. The reversal of 261355 is 553162.

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 261355 - 2¹ = 261353 is a prime.

It is a Duffinian number.

261355 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (261353) 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, 679 + ... + 991.

It is an arithmetic number, because the mean of its divisors is an integer number (39564).

2²⁶¹³⁵⁵ is an apocalyptic number.

261355 is a deficient number, since it is larger than the sum of its proper divisors (55157).

261355 is a wasteful number, since it uses less digits than its factorization.

261355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 485.

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

The square root of 261355 is about 511.2289115455. The cubic root of 261355 is about 63.9357264890.

It can be divided in two parts, 261 and 355, that added together give a palindrome (616).

The spelling of 261355 in words is "two hundred sixty-one thousand, three hundred fifty-five".