261398035441 has 27 divisors (see below), whose sum is σ = 280560541113. Its totient is φ = 243508151880.

The previous prime is 261398035417. The next prime is 261398035487. The reversal of 261398035441 is 144530893162.

It is a happy number.

The square root of 261398035441 is 511271.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 261398035441 - 2²¹ = 261395938289 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261398035391 and 261398035400.

It is not an unprimeable number, because it can be changed into a prime (261398005441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 689704390 + ... + 689704768.

Almost surely, 2^261398035441 is an apocalyptic number.

261398035441 is the 511271-st square number.

261398035441 is the 255636-th centered octagonal number.

It is an amenable number.

261398035441 is a deficient number, since it is larger than the sum of its proper divisors (19162505672).

261398035441 is an frugal number, since it uses more digits than its factorization.

261398035441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 938 (or 469 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 46.

The spelling of 261398035441 in words is "two hundred sixty-one billion, three hundred ninety-eight million, thirty-five thousand, four hundred forty-one".