261016560 has 320 divisors, whose sum is σ = 1048028160. Its totient is φ = 58475520.

The previous prime is 261016543. The next prime is 261016571. The reversal of 261016560 is 65610162.

It is a happy number.

261016560 is a `hidden beast` number, since 2 + 6 + 1 + 0 + 1 + 656 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 922179 + ... + 922461.

It is an arithmetic number, because the mean of its divisors is an integer number (3275088).

Almost surely, 2^261016560 is an apocalyptic number.

261016560 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 261016560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (524014080).

261016560 is an abundant number, since it is smaller than the sum of its proper divisors (787011600).

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

261016560 is a wasteful number, since it uses less digits than its factorization.

261016560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373 (or 361 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 261016560 is about 16156.0069324075. The cubic root of 261016560 is about 639.0811684677.

The spelling of 261016560 in words is "two hundred sixty-one million, sixteen thousand, five hundred sixty".