261550477650 has 288 divisors, whose sum is σ = 824081755392. Its totient is φ = 54286108800.

The previous prime is 261550477633. The next prime is 261550477651. The reversal of 261550477650 is 56774055162.

261550477650 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 261550477650.

It is not an unprimeable number, because it can be changed into a prime (261550477651) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 115371817 + ... + 115374083.

It is an arithmetic number, because the mean of its divisors is an integer number (2861394984).

Almost surely, 2^261550477650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261550477650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (412040877696).

261550477650 is an abundant number, since it is smaller than the sum of its proper divisors (562531277742).

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

261550477650 is a wasteful number, since it uses less digits than its factorization.

261550477650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3734 (or 3722 counting only the distinct ones).

The product of its (nonzero) digits is 1764000, while the sum is 48.

The spelling of 261550477650 in words is "two hundred sixty-one billion, five hundred fifty million, four hundred seventy-seven thousand, six hundred fifty".