261088728 has 64 divisors (see below), whose sum is σ = 689520000. Its totient is φ = 82156032.

The previous prime is 261088721. The next prime is 261088741. The reversal of 261088728 is 827880162.

It is a self number, because there is not a number n which added to its sum of digits gives 261088728.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261088721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 152823 + ... + 154521.

It is an arithmetic number, because the mean of its divisors is an integer number (10773750).

Almost surely, 2^261088728 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 261088728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (344760000).

261088728 is an abundant number, since it is smaller than the sum of its proper divisors (428431272).

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

261088728 is a wasteful number, since it uses less digits than its factorization.

261088728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2064 (or 2060 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 42.

The square root of 261088728 is about 16158.2402507204. The cubic root of 261088728 is about 639.1400625084.

The spelling of 261088728 in words is "two hundred sixty-one million, eighty-eight thousand, seven hundred twenty-eight".