261557296 has 120 divisors (see below), whose sum is σ = 692861904. Its totient is φ = 94026240.

The previous prime is 261557281. The next prime is 261557333. The reversal of 261557296 is 692755162.

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, 110946 + ... + 113278.

Almost surely, 2^261557296 is an apocalyptic number.

261557296 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 261557296, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (346430952).

261557296 is an abundant number, since it is smaller than the sum of its proper divisors (431304608).

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

261557296 is a wasteful number, since it uses less digits than its factorization.

261557296 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2379 (or 2366 counting only the distinct ones).

The product of its digits is 226800, while the sum is 43.

The square root of 261557296 is about 16172.7331023547. The cubic root of 261557296 is about 639.5221824175.

The spelling of 261557296 in words is "two hundred sixty-one million, five hundred fifty-seven thousand, two hundred ninety-six".