261238102520 has 64 divisors (see below), whose sum is σ = 589244958720. Its totient is φ = 104236066944.

The previous prime is 261238102481. The next prime is 261238102529. The reversal of 261238102520 is 25201832162.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261238102529) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66251669 + ... + 66255611.

It is an arithmetic number, because the mean of its divisors is an integer number (9206952480).

Almost surely, 2^261238102520 is an apocalyptic number.

261238102520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261238102520 is an abundant number, since it is smaller than the sum of its proper divisors (328006856200).

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

261238102520 is a wasteful number, since it uses less digits than its factorization.

261238102520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7644 (or 7640 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

Adding to 261238102520 its reverse (25201832162), we get a palindrome (286439934682).

The spelling of 261238102520 in words is "two hundred sixty-one billion, two hundred thirty-eight million, one hundred two thousand, five hundred twenty".