261982020265056 has 1944 divisors, whose sum is σ = 977398997479632. Its totient is φ = 66334754304000.

The previous prime is 261982020265039. The next prime is 261982020265103. The reversal of 261982020265056 is 650562020289162.

It is a happy number.

261982020265056 is a `hidden beast` number, since 2 + 6 + 1 + 98 + 2 + 0 + 20 + 26 + 505 + 6 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 261982020264993 and 261982020265011.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 323 ways as a sum of consecutive naturals, for example, 346079286630 + ... + 346079287386.

It is an arithmetic number, because the mean of its divisors is an integer number (502777262078).

Almost surely, 2^{261982020265056} is an apocalyptic number.

261982020265056 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261982020265056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (488699498739816).

261982020265056 is an abundant number, since it is smaller than the sum of its proper divisors (715416977214576).

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

261982020265056 is a wasteful number, since it uses less digits than its factorization.

261982020265056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1026 (or 964 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 54.

The spelling of 261982020265056 in words is "two hundred sixty-one trillion, nine hundred eighty-two billion, twenty million, two hundred sixty-five thousand, fifty-six".