261501130642820 has 24 divisors (see below), whose sum is σ = 551571547814784. Its totient is φ = 104139657311456.

The previous prime is 261501130642783. The next prime is 261501130642823. The reversal of 261501130642820 is 28246031105162.

It is not an unprimeable number, because it can be changed into a prime (261501130642823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28799679452 + ... + 28799688531.

It is an arithmetic number, because the mean of its divisors is an integer number (22982147825616).

Almost surely, 2^{261501130642820} is an apocalyptic number.

261501130642820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261501130642820 is an abundant number, since it is smaller than the sum of its proper divisors (290070417171964).

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

261501130642820 is a wasteful number, since it uses less digits than its factorization.

261501130642820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57599368219 (or 57599368217 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 41.

Adding to 261501130642820 its reverse (28246031105162), we get a palindrome (289747161747982).

The spelling of 261501130642820 in words is "two hundred sixty-one trillion, five hundred one billion, one hundred thirty million, six hundred forty-two thousand, eight hundred twenty".