261336465125 has 48 divisors (see below), whose sum is σ = 335843398800. Its totient is φ = 202911744000.

The previous prime is 261336465113. The next prime is 261336465127. The reversal of 261336465125 is 521564633162.

It can be written as a sum of positive squares in 24 ways, for example, as 240601041121 + 20735424004 = 490511^2 + 143998^2 .

It is not a de Polignac number, because 261336465125 - 2¹⁴ = 261336448741 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261336465127) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 582040901 + ... + 582041349.

It is an arithmetic number, because the mean of its divisors is an integer number (6996737475).

Almost surely, 2^261336465125 is an apocalyptic number.

261336465125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261336465125 is a deficient number, since it is larger than the sum of its proper divisors (74506933675).

261336465125 is an frugal number, since it uses more digits than its factorization.

261336465125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1179 (or 832 counting only the distinct ones).

The product of its digits is 777600, while the sum is 44.

The spelling of 261336465125 in words is "two hundred sixty-one billion, three hundred thirty-six million, four hundred sixty-five thousand, one hundred twenty-five".