261178577712 has 320 divisors, whose sum is σ = 821536168320. Its totient is φ = 78962688000.

The previous prime is 261178577687. The next prime is 261178577719. The reversal of 261178577712 is 217775871162.

261178577712 is a `hidden beast` number, since 2 + 61 + 1 + 7 + 8 + 577 + 7 + 1 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (261178577719) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 77706912 + ... + 77710272.

It is an arithmetic number, because the mean of its divisors is an integer number (2567300526).

Almost surely, 2^261178577712 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 261178577712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (410768084160).

261178577712 is an abundant number, since it is smaller than the sum of its proper divisors (560357590608).

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

261178577712 is a wasteful number, since it uses less digits than its factorization.

261178577712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3629 (or 3617 counting only the distinct ones).

The product of its digits is 2304960, while the sum is 54.

The spelling of 261178577712 in words is "two hundred sixty-one billion, one hundred seventy-eight million, five hundred seventy-seven thousand, seven hundred twelve".