261404 has 24 divisors (see below), whose sum is σ = 538608. Its totient is φ = 109440.

The previous prime is 261389. The next prime is 261407. The reversal of 261404 is 404162.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 261404.

It is not an unprimeable number, because it can be changed into a prime (261407) by changing a digit.

261404 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 344 + ... + 800.

It is an arithmetic number, because the mean of its divisors is an integer number (22442).

2²⁶¹⁴⁰⁴ is an apocalyptic number.

It is an amenable number.

261404 is an abundant number, since it is smaller than the sum of its proper divisors (277204).

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

261404 is a wasteful number, since it uses less digits than its factorization.

261404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 485 (or 483 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 261404 is about 511.2768330367. The cubic root of 261404 is about 63.9397218910.

Adding to 261404 its reverse (404162), we get a palindrome (665566).

The spelling of 261404 in words is "two hundred sixty-one thousand, four hundred four".