261583456 has 48 divisors (see below), whose sum is σ = 535127040. Its totient is φ = 125735040.

The previous prime is 261583453. The next prime is 261583459. The reversal of 261583456 is 654385162.

It is an interprime number because it is at equal distance from previous prime (261583453) and next prime (261583459).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261583453) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 164875 + ... + 166453.

It is an arithmetic number, because the mean of its divisors is an integer number (11148480).

Almost surely, 2^261583456 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 261583456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (267563520).

261583456 is an abundant number, since it is smaller than the sum of its proper divisors (273543584).

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

261583456 is a wasteful number, since it uses less digits than its factorization.

261583456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1787 (or 1779 counting only the distinct ones).

The product of its digits is 172800, while the sum is 40.

The square root of 261583456 is about 16173.5418508130. The cubic root of 261583456 is about 639.5435025932.

The spelling of 261583456 in words is "two hundred sixty-one million, five hundred eighty-three thousand, four hundred fifty-six".