261724728 has 64 divisors (see below), whose sum is σ = 685843200. Its totient is φ = 83072000.

The previous prime is 261724711. The next prime is 261724763. The reversal of 261724728 is 827427162.

261724728 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 137608 + ... + 139496.

It is an arithmetic number, because the mean of its divisors is an integer number (10716300).

Almost surely, 2^261724728 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 261724728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (342921600).

261724728 is an abundant number, since it is smaller than the sum of its proper divisors (424118472).

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

261724728 is a wasteful number, since it uses less digits than its factorization.

261724728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2172 (or 2168 counting only the distinct ones).

The product of its digits is 75264, while the sum is 39.

The square root of 261724728 is about 16177.9086411069. The cubic root of 261724728 is about 639.6586135041.

The spelling of 261724728 in words is "two hundred sixty-one million, seven hundred twenty-four thousand, seven hundred twenty-eight".