261105280 has 32 divisors (see below), whose sum is σ = 624206340. Its totient is φ = 104441856.

The previous prime is 261105259. The next prime is 261105289. The reversal of 261105280 is 82501162.

It can be written as a sum of positive squares in 2 ways, for example, as 247621696 + 13483584 = 15736^2 + 3672^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (261105289) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 203349 + ... + 204628.

Almost surely, 2^261105280 is an apocalyptic number.

261105280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261105280 is an abundant number, since it is smaller than the sum of its proper divisors (363101060).

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

261105280 is an equidigital number, since it uses as much as digits as its factorization.

261105280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407996 (or 407984 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 261105280 is about 16158.7524270904. The cubic root of 261105280 is about 639.1535685463.

The spelling of 261105280 in words is "two hundred sixty-one million, one hundred five thousand, two hundred eighty".