261371760216 has 128 divisors (see below), whose sum is σ = 767056711680. Its totient is φ = 72676492416.

The previous prime is 261371760197. The next prime is 261371760233. The reversal of 261371760216 is 612067173162.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 794365 + ... + 1074131.

It is an arithmetic number, because the mean of its divisors is an integer number (5992630560).

Almost surely, 2^261371760216 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 261371760216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (383528355840).

261371760216 is an abundant number, since it is smaller than the sum of its proper divisors (505684951464).

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

261371760216 is a wasteful number, since it uses less digits than its factorization.

261371760216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279933 (or 279929 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 42.

The spelling of 261371760216 in words is "two hundred sixty-one billion, three hundred seventy-one million, seven hundred sixty thousand, two hundred sixteen".