261431216661344 has 192 divisors, whose sum is σ = 556931803825152. Its totient is φ = 120353729126400.

The previous prime is 261431216661319. The next prime is 261431216661347. The reversal of 261431216661344 is 443166612134162.

261431216661344 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 261431216661292 and 261431216661301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261431216661347) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3560677754 + ... + 3560751174.

It is an arithmetic number, because the mean of its divisors is an integer number (2900686478256).

Almost surely, 2^{261431216661344} 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 261431216661344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (278465901912576).

261431216661344 is an abundant number, since it is smaller than the sum of its proper divisors (295500587163808).

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

261431216661344 is a wasteful number, since it uses less digits than its factorization.

261431216661344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74189 (or 74181 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 50.

The spelling of 261431216661344 in words is "two hundred sixty-one trillion, four hundred thirty-one billion, two hundred sixteen million, six hundred sixty-one thousand, three hundred forty-four".