261893 has 4 divisors (see below), whose sum is σ = 264588. Its totient is φ = 259200.

The previous prime is 261887. The next prime is 261917. The reversal of 261893 is 398162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 398162 = 2 ⋅199081.

It can be written as a sum of positive squares in 2 ways, for example, as 214369 + 47524 = 463^2 + 218^2 .

It is a cyclic number.

It is not a de Polignac number, because 261893 - 2⁸ = 261637 is a prime.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261823) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1196 + ... + 1397.

It is an arithmetic number, because the mean of its divisors is an integer number (66147).

2²⁶¹⁸⁹³ is an apocalyptic number.

It is an amenable number.

261893 is a deficient number, since it is larger than the sum of its proper divisors (2695).

261893 is a wasteful number, since it uses less digits than its factorization.

261893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2694.

The product of its digits is 2592, while the sum is 29.

The square root of 261893 is about 511.7548241101. The cubic root of 261893 is about 63.9795670449.

The spelling of 261893 in words is "two hundred sixty-one thousand, eight hundred ninety-three".