261380 has 24 divisors (see below), whose sum is σ = 627648. Its totient is φ = 89568.

The previous prime is 261379. The next prime is 261389. The reversal of 261380 is 83162.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (261389) 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, 794 + ... + 1073.

It is an arithmetic number, because the mean of its divisors is an integer number (26152).

2²⁶¹³⁸⁰ is an apocalyptic number.

261380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261380 is an abundant number, since it is smaller than the sum of its proper divisors (366268).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261380 is a wasteful number, since it uses less digits than its factorization.

261380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1883 (or 1881 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 261380 is about 511.2533618471. The cubic root of 261380 is about 63.9377650218.

It can be divided in two parts, 2 and 61380, that multiplied together give a triangular number (122760 = T₄₉₅).

The spelling of 261380 in words is "two hundred sixty-one thousand, three hundred eighty".