261244260 has 72 divisors (see below), whose sum is σ = 795969720. Its totient is φ = 69355008.

The previous prime is 261244213. The next prime is 261244289. The reversal of 261244260 is 62442162.

261244260 is a `hidden beast` number, since 2 + 612 + 4 + 42 + 6 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 7096896 + 254147364 = 2664^2 + 15942^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 38826 + ... + 45054.

It is an arithmetic number, because the mean of its divisors is an integer number (11055135).

Almost surely, 2^261244260 is an apocalyptic number.

261244260 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 261244260, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (397984860).

261244260 is an abundant number, since it is smaller than the sum of its proper divisors (534725460).

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

261244260 is a wasteful number, since it uses less digits than its factorization.

261244260 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6477 (or 6472 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 261244260 is about 16163.0523107487. The cubic root of 261244260 is about 639.2669504064.

The spelling of 261244260 in words is "two hundred sixty-one million, two hundred forty-four thousand, two hundred sixty".