261510081525 has 144 divisors (see below), whose sum is σ = 605600905728. Its totient is φ = 108679320000.

The previous prime is 261510081509. The next prime is 261510081533. The reversal of 261510081525 is 525180015162.

261510081525 is a `hidden beast` number, since 2 + 6 + 1 + 51 + 0 + 0 + 81 + 525 = 666.

It is not a de Polignac number, because 261510081525 - 2⁴ = 261510081509 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261510081525.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 188250 + ... + 747300.

Almost surely, 2^261510081525 is an apocalyptic number.

261510081525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261510081525 is an abundant number, since it is smaller than the sum of its proper divisors (344090824203).

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

261510081525 is a wasteful number, since it uses less digits than its factorization.

261510081525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 559094 (or 559077 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 36.

Adding to 261510081525 its reverse (525180015162), we get a palindrome (786690096687).

The spelling of 261510081525 in words is "two hundred sixty-one billion, five hundred ten million, eighty-one thousand, five hundred twenty-five".