261543677504066 has 16 divisors (see below), whose sum is σ = 393507477373248. Its totient is φ = 130374531870000.

The previous prime is 261543677504047. The next prime is 261543677504111. The reversal of 261543677504066 is 660405776345162.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35776691 + ... + 42462441.

It is an arithmetic number, because the mean of its divisors is an integer number (24594217335828).

Almost surely, 2^{261543677504066} is an apocalyptic number.

261543677504066 is a deficient number, since it is larger than the sum of its proper divisors (131963799869182).

261543677504066 is a wasteful number, since it uses less digits than its factorization.

261543677504066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6745177.

The product of its (nonzero) digits is 152409600, while the sum is 62.

The spelling of 261543677504066 in words is "two hundred sixty-one trillion, five hundred forty-three billion, six hundred seventy-seven million, five hundred four thousand, sixty-six".