261442404 has 60 divisors (see below), whose sum is σ = 700167468. Its totient is φ = 85017600.

The previous prime is 261442399. The next prime is 261442417. The reversal of 261442404 is 404244162.

It is a happy number.

261442404 is a `hidden beast` number, since 2 + 614 + 4 + 2 + 40 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 142850304 + 118592100 = 11952^2 + 10890^2 .

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3444 + ... + 23124.

Almost surely, 2^261442404 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261442404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (350083734).

261442404 is an abundant number, since it is smaller than the sum of its proper divisors (438725064).

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

261442404 is a wasteful number, since it uses less digits than its factorization.

261442404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19738 (or 19727 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 27.

The square root of 261442404 is about 16169.1806842524. The cubic root of 261442404 is about 639.4285295866.

Adding to 261442404 its reverse (404244162), we get a palindrome (665686566).

The spelling of 261442404 in words is "two hundred sixty-one million, four hundred forty-two thousand, four hundred four".