261689226669556 has 72 divisors (see below), whose sum is σ = 533453641614600. Its totient is φ = 111999035860992.

The previous prime is 261689226669517. The next prime is 261689226669569. The reversal of 261689226669556 is 655966622986162.

261689226669556 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 82859693452900 + 178829533216656 = 9102730^2 + 13372716^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6060826240 + ... + 6060869416.

Almost surely, 2^{261689226669556} is an apocalyptic number.

It is an amenable number.

261689226669556 is an abundant number, since it is smaller than the sum of its proper divisors (271764414945044).

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

261689226669556 is a wasteful number, since it uses less digits than its factorization.

261689226669556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84801 (or 84792 counting only the distinct ones).

The product of its digits is 6046617600, while the sum is 79.

The spelling of 261689226669556 in words is "two hundred sixty-one trillion, six hundred eighty-nine billion, two hundred twenty-six million, six hundred sixty-nine thousand, five hundred fifty-six".