261691246619968 has 56 divisors (see below), whose sum is σ = 569468053384704. Its totient is φ = 118327788748800.

The previous prime is 261691246619903. The next prime is 261691246619983. The reversal of 261691246619968 is 869916642196162.

261691246619968 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 261691246619894 and 261691246619903.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 972955905 + ... + 973224832.

Almost surely, 2^{261691246619968} is an apocalyptic number.

It is an amenable number.

261691246619968 is an abundant number, since it is smaller than the sum of its proper divisors (307776806764736).

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

261691246619968 is a wasteful number, since it uses less digits than its factorization.

261691246619968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1946180951 (or 1946180941 counting only the distinct ones).

The product of its digits is 725594112, while the sum is 76.

The spelling of 261691246619968 in words is "two hundred sixty-one trillion, six hundred ninety-one billion, two hundred forty-six million, six hundred nineteen thousand, nine hundred sixty-eight".