261404512 has 48 divisors (see below), whose sum is σ = 548992080. Its totient is φ = 122093568.

The previous prime is 261404503. The next prime is 261404513. The reversal of 261404512 is 215404162.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261404513) 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, 73888 + ... + 77344.

It is an arithmetic number, because the mean of its divisors is an integer number (11437335).

Almost surely, 2^261404512 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 261404512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (274496040).

261404512 is an abundant number, since it is smaller than the sum of its proper divisors (287587568).

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

261404512 is a wasteful number, since it uses less digits than its factorization.

261404512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3623 (or 3615 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 261404512 is about 16168.0089064795. The cubic root of 261404512 is about 639.3976363623.

Adding to 261404512 its reverse (215404162), we get a palindrome (476808674).

The spelling of 261404512 in words is "two hundred sixty-one million, four hundred four thousand, five hundred twelve".