261344616 has 64 divisors (see below), whose sum is σ = 722668800. Its totient is φ = 78236928.

The previous prime is 261344597. The next prime is 261344617. The reversal of 261344616 is 616443162.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (261344617) 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, 225 + ... + 22863.

It is an arithmetic number, because the mean of its divisors is an integer number (11291700).

Almost surely, 2^261344616 is an apocalyptic number.

261344616 is a gapful number since it is divisible by the number (26) 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 261344616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (361334400).

261344616 is an abundant number, since it is smaller than the sum of its proper divisors (461324184).

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

261344616 is a wasteful number, since it uses less digits than its factorization.

261344616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22698 (or 22694 counting only the distinct ones).

The product of its digits is 20736, while the sum is 33.

The square root of 261344616 is about 16166.1565005415. The cubic root of 261344616 is about 639.3487972586.

Adding to 261344616 its reverse (616443162), we get a palindrome (877787778).

The spelling of 261344616 in words is "two hundred sixty-one million, three hundred forty-four thousand, six hundred sixteen".