261396025344 has 182 divisors, whose sum is σ = 783742778546. Its totient is φ = 87131013120.

The previous prime is 261396025339. The next prime is 261396025351. The reversal of 261396025344 is 443520693162.

261396025344 is a `hidden beast` number, since 2 + 6 + 1 + 3 + 9 + 602 + 5 + 34 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 217678233600 + 43717791744 = 466560^2 + 209088^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 261396025344.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 2942214 + ... + 3029754.

It is an arithmetic number, because the mean of its divisors is an integer number (4306279003).

Almost surely, 2^261396025344 is an apocalyptic number.

261396025344 is a gapful number since it is divisible by the number (24) 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 261396025344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (391871389273).

261396025344 is an abundant number, since it is smaller than the sum of its proper divisors (522346753202).

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

261396025344 is an frugal number, since it uses more digits than its factorization.

261396025344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87583 (or 87546 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 45.

The spelling of 261396025344 in words is "two hundred sixty-one billion, three hundred ninety-six million, twenty-five thousand, three hundred forty-four".