261532720 has 80 divisors (see below), whose sum is σ = 649110240. Its totient is φ = 97708032.

The previous prime is 261532703. The next prime is 261532721. The reversal of 261532720 is 27235162.

261532720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (261532721) 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, 109782 + ... + 112138.

It is an arithmetic number, because the mean of its divisors is an integer number (8113878).

Almost surely, 2^261532720 is an apocalyptic number.

261532720 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 261532720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (324555120).

261532720 is an abundant number, since it is smaller than the sum of its proper divisors (387577520).

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

261532720 is a wasteful number, since it uses less digits than its factorization.

261532720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2462 (or 2456 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 261532720 is about 16171.9732871409. The cubic root of 261532720 is about 639.5021518930.

Adding to 261532720 its reverse (27235162), we get a palindrome (288767882).

The spelling of 261532720 in words is "two hundred sixty-one million, five hundred thirty-two thousand, seven hundred twenty".