261665573374016 has 28 divisors (see below), whose sum is σ = 593420139617088. Its totient is φ = 112142388588672.

The previous prime is 261665573374003. The next prime is 261665573374039. The reversal of 261665573374016 is 610473375566162.

It is a tau number, because it is divible by the number of its divisors (28).

It is a self number, because there is not a number n which added to its sum of digits gives 261665573374016.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 292037469836 + ... + 292037470731.

It is an arithmetic number, because the mean of its divisors is an integer number (21193576414896).

Almost surely, 2^{261665573374016} is an apocalyptic number.

It is an amenable number.

261665573374016 is an abundant number, since it is smaller than the sum of its proper divisors (331754566243072).

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

261665573374016 is an equidigital number, since it uses as much as digits as its factorization.

261665573374016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 584074940586 (or 584074940576 counting only the distinct ones).

The product of its (nonzero) digits is 114307200, while the sum is 62.

The spelling of 261665573374016 in words is "two hundred sixty-one trillion, six hundred sixty-five billion, five hundred seventy-three million, three hundred seventy-four thousand, sixteen".