261823567138056 has 192 divisors, whose sum is σ = 884242883422080. Its totient is φ = 67993559331840.

The previous prime is 261823567137959. The next prime is 261823567138057. The reversal of 261823567138056 is 650831765328162.

261823567138056 is a `hidden beast` number, since 2 + 6 + 1 + 8 + 2 + 3 + 567 + 13 + 8 + 0 + 56 = 666.

It is a super-2 number, since 2×261823567138056² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a junction number, because it is equal to n+sod(n) for n = 261823567137984 and 261823567138002.

It is not an unprimeable number, because it can be changed into a prime (261823567138057) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 25672750 + ... + 34390946.

It is an arithmetic number, because the mean of its divisors is an integer number (4605431684490).

Almost surely, 2^{261823567138056} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261823567138056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (442121441711040).

261823567138056 is an abundant number, since it is smaller than the sum of its proper divisors (622419316284024).

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

261823567138056 is a wasteful number, since it uses less digits than its factorization.

261823567138056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8723644 (or 8723637 counting only the distinct ones).

The product of its (nonzero) digits is 87091200, while the sum is 63.

The spelling of 261823567138056 in words is "two hundred sixty-one trillion, eight hundred twenty-three billion, five hundred sixty-seven million, one hundred thirty-eight thousand, fifty-six".