261246440 has 96 divisors (see below), whose sum is σ = 736442280. Its totient is φ = 82672128.

The previous prime is 261246437. The next prime is 261246449. The reversal of 261246440 is 44642162.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 107039716 + 154206724 = 10346^2 + 12418^2 .

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (261246449) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20354 + ... + 30606.

Almost surely, 2^261246440 is an apocalyptic number.

261246440 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 261246440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (368221140).

261246440 is an abundant number, since it is smaller than the sum of its proper divisors (475195840).

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

261246440 is a wasteful number, since it uses less digits than its factorization.

261246440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10291 (or 10280 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 29.

The square root of 261246440 is about 16163.1197483654. The cubic root of 261246440 is about 639.2687285611.

The spelling of 261246440 in words is "two hundred sixty-one million, two hundred forty-six thousand, four hundred forty".