261530880 has 288 divisors, whose sum is σ = 934026240. Its totient is φ = 62300160.

The previous prime is 261530869. The next prime is 261530881. The reversal of 261530880 is 88035162.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261530881) 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, 8436465 + ... + 8436495.

Almost surely, 2^261530880 is an apocalyptic number.

261530880 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 261530880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (467013120).

261530880 is an abundant number, since it is smaller than the sum of its proper divisors (672495360).

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

261530880 is an equidigital number, since it uses as much as digits as its factorization.

261530880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94 (or 54 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 261530880 is about 16171.9163984977. The cubic root of 261530880 is about 639.5006521613.

The spelling of 261530880 in words is "two hundred sixty-one million, five hundred thirty thousand, eight hundred eighty".