261335880 has 192 divisors, whose sum is σ = 963144000. Its totient is φ = 60922368.

The previous prime is 261335873. The next prime is 261335881. The reversal of 261335880 is 88533162.

261335880 is a `hidden beast` number, since 2 + 613 + 35 + 8 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (261335881) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 87451 + ... + 90389.

It is an arithmetic number, because the mean of its divisors is an integer number (5016375).

Almost surely, 2^261335880 is an apocalyptic number.

261335880 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 261335880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (481572000).

261335880 is an abundant number, since it is smaller than the sum of its proper divisors (701808120).

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

261335880 is a wasteful number, since it uses less digits than its factorization.

261335880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2988 (or 2981 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 261335880 is about 16165.8863041901. The cubic root of 261335880 is about 639.3416733144.

The spelling of 261335880 in words is "two hundred sixty-one million, three hundred thirty-five thousand, eight hundred eighty".