261544416 has 192 divisors, whose sum is σ = 823076352. Its totient is φ = 71165952.

The previous prime is 261544411. The next prime is 261544553. The reversal of 261544416 is 614445162.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261544411) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1665810 + ... + 1665966.

It is an arithmetic number, because the mean of its divisors is an integer number (4286856).

Almost surely, 2^261544416 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261544416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (411538176).

261544416 is an abundant number, since it is smaller than the sum of its proper divisors (561531936).

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

261544416 is a wasteful number, since it uses less digits than its factorization.

261544416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281 (or 273 counting only the distinct ones).

The product of its digits is 23040, while the sum is 33.

The square root of 261544416 is about 16172.3348963593. The cubic root of 261544416 is about 639.5116848056.

Adding to 261544416 its reverse (614445162), we get a palindrome (875989578).

The spelling of 261544416 in words is "two hundred sixty-one million, five hundred forty-four thousand, four hundred sixteen".