261278908975680 has 896 divisors, whose sum is σ = 907788697804800. Its totient is φ = 63491707699200.

The previous prime is 261278908975603. The next prime is 261278908975691. The reversal of 261278908975680 is 86579809872162.

It is a junction number, because it is equal to n+sod(n) for n = 261278908975596 and 261278908975605.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 7675852101 + ... + 7675886139.

It is an arithmetic number, because the mean of its divisors is an integer number (1013157028800).

Almost surely, 2^{261278908975680} is an apocalyptic number.

261278908975680 is a gapful number since it is divisible by the number (20) 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 261278908975680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (453894348902400).

261278908975680 is an abundant number, since it is smaller than the sum of its proper divisors (646509788829120).

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

261278908975680 is a wasteful number, since it uses less digits than its factorization.

261278908975680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34323 (or 34313 counting only the distinct ones).

The product of its (nonzero) digits is 1463132160, while the sum is 78.

The spelling of 261278908975680 in words is "two hundred sixty-one trillion, two hundred seventy-eight billion, nine hundred eight million, nine hundred seventy-five thousand, six hundred eighty".