261283216320 has 2240 divisors, whose sum is σ = 1223616430080. Its totient is φ = 51502252032.

The previous prime is 261283216309. The next prime is 261283216391. The reversal of 261283216320 is 23612382162.

261283216320 is a `hidden beast` number, since 2 + 6 + 1 + 2 + 8 + 321 + 6 + 320 = 666.

It is a tau number, because it is divible by the number of its divisors (2240).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 2057348097 + ... + 2057348223.

Almost surely, 2^261283216320 is an apocalyptic number.

261283216320 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 261283216320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (611808215040).

261283216320 is an abundant number, since it is smaller than the sum of its proper divisors (962333213760).

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

261283216320 is a wasteful number, since it uses less digits than its factorization.

261283216320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232 (or 213 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

Adding to 261283216320 its reverse (23612382162), we get a palindrome (284895598482).

The spelling of 261283216320 in words is "two hundred sixty-one billion, two hundred eighty-three million, two hundred sixteen thousand, three hundred twenty".