261684 has 24 divisors (see below), whose sum is σ = 678720. Its totient is φ = 87192.

The previous prime is 261673. The next prime is 261697. The reversal of 261684 is 486162.

261684 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1104 + ... + 1319.

It is an arithmetic number, because the mean of its divisors is an integer number (28280).

2²⁶¹⁶⁸⁴ is an apocalyptic number.

It is an amenable number.

261684 is an abundant number, since it is smaller than the sum of its proper divisors (417036).

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

261684 is a wasteful number, since it uses less digits than its factorization.

261684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2436 (or 2428 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 261684 is about 511.5505840090. The cubic root of 261684 is about 63.9625431864.

The spelling of 261684 in words is "two hundred sixty-one thousand, six hundred eighty-four".