261345 has 32 divisors (see below), whose sum is σ = 506880. Its totient is φ = 112320.

The previous prime is 261337. The next prime is 261347. The reversal of 261345 is 543162.

It is a happy number.

261345 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 261345 - 2³ = 261337 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

261345 is strictly pandigital in base 7.

It is not an unprimeable number, because it can be changed into a prime (261347) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1930 + ... + 2060.

It is an arithmetic number, because the mean of its divisors is an integer number (15840).

2²⁶¹³⁴⁵ is an apocalyptic number.

It is an amenable number.

261345 is a deficient number, since it is larger than the sum of its proper divisors (245535).

261345 is a wasteful number, since it uses less digits than its factorization.

261345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165.

The product of its digits is 720, while the sum is 21.

The square root of 261345 is about 511.2191310974. The cubic root of 261345 is about 63.9349110395.

It can be divided in two parts, 261 and 345, that added together give a palindrome (606).

The spelling of 261345 in words is "two hundred sixty-one thousand, three hundred forty-five".