261303373056 has 144 divisors (see below), whose sum is σ = 766038873600. Its totient is φ = 78413813760.

The previous prime is 261303373049. The next prime is 261303373069. The reversal of 261303373056 is 650373303162.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 719995 + ... + 1020293.

It is an arithmetic number, because the mean of its divisors is an integer number (5319714400).

Almost surely, 2^261303373056 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 261303373056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (383019436800).

261303373056 is an abundant number, since it is smaller than the sum of its proper divisors (504735500544).

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

261303373056 is a wasteful number, since it uses less digits than its factorization.

261303373056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300432 (or 300418 counting only the distinct ones).

The product of its (nonzero) digits is 204120, while the sum is 39.

The spelling of 261303373056 in words is "two hundred sixty-one billion, three hundred three million, three hundred seventy-three thousand, fifty-six".