261567684 has 192 divisors, whose sum is σ = 827904000. Its totient is φ = 71251488.

The previous prime is 261567653. The next prime is 261567697. The reversal of 261567684 is 486765162.

261567684 is a `hidden beast` number, since 2 + 6 + 1 + 567 + 6 + 84 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 851859 + ... + 852165.

It is an arithmetic number, because the mean of its divisors is an integer number (4312000).

Almost surely, 2^261567684 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 261567684, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (413952000).

261567684 is an abundant number, since it is smaller than the sum of its proper divisors (566336316).

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

261567684 is a wasteful number, since it uses less digits than its factorization.

261567684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364 (or 342 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 261567684 is about 16173.0542570041. The cubic root of 261567684 is about 639.5306487186.

The spelling of 261567684 in words is "two hundred sixty-one million, five hundred sixty-seven thousand, six hundred eighty-four".