261241630500 has 192 divisors, whose sum is σ = 801320083200. Its totient is φ = 65952921600.

The previous prime is 261241630499. The next prime is 261241630511. The reversal of 261241630500 is 5036142162.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 67172556 + ... + 67176444.

It is an arithmetic number, because the mean of its divisors is an integer number (4173542100).

Almost surely, 2^261241630500 is an apocalyptic number.

261241630500 is a gapful number since it is divisible by the number (20) 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 261241630500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (400660041600).

261241630500 is an abundant number, since it is smaller than the sum of its proper divisors (540078452700).

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

261241630500 is a wasteful number, since it uses less digits than its factorization.

261241630500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6287 (or 6275 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

Adding to 261241630500 its reverse (5036142162), we get a palindrome (266277772662).

The spelling of 261241630500 in words is "two hundred sixty-one billion, two hundred forty-one million, six hundred thirty thousand, five hundred".