261330720 has 288 divisors, whose sum is σ = 984566016. Its totient is φ = 58060800.

The previous prime is 261330709. The next prime is 261330743. The reversal of 261330720 is 27033162.

261330720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 964185 + ... + 964455.

It is an arithmetic number, because the mean of its divisors is an integer number (3418632).

Almost surely, 2^261330720 is an apocalyptic number.

261330720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261330720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (492283008).

261330720 is an abundant number, since it is smaller than the sum of its proper divisors (723235296).

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

261330720 is a wasteful number, since it uses less digits than its factorization.

261330720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344 (or 329 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 24.

The square root of 261330720 is about 16165.7267080698. The cubic root of 261330720 is about 639.3374654157.

Adding to 261330720 its reverse (27033162), we get a palindrome (288363882).

It can be divided in two parts, 2613 and 30720, that added together give a palindrome (33333).

The spelling of 261330720 in words is "two hundred sixty-one million, three hundred thirty thousand, seven hundred twenty".