261578326266 has 32 divisors (see below), whose sum is σ = 588643219200. Its totient is φ = 86089068000.

The previous prime is 261578326253. The next prime is 261578326267. The reversal of 261578326266 is 662623875162.

261578326266 is a `hidden beast` number, since 2 + 6 + 1 + 5 + 7 + 8 + 3 + 2 + 626 + 6 = 666.

261578326266 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 (261578326267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30654235 + ... + 30662766.

It is an arithmetic number, because the mean of its divisors is an integer number (18395100600).

Almost surely, 2^261578326266 is an apocalyptic number.

261578326266 is an abundant number, since it is smaller than the sum of its proper divisors (327064892934).

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

261578326266 is a wasteful number, since it uses less digits than its factorization.

261578326266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61317091 (or 61317085 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 54.

The spelling of 261578326266 in words is "two hundred sixty-one billion, five hundred seventy-eight million, three hundred twenty-six thousand, two hundred sixty-six".