261163136420 has 48 divisors (see below), whose sum is σ = 557608181760. Its totient is φ = 102724917504.

The previous prime is 261163136411. The next prime is 261163136447. The reversal of 261163136420 is 24631361162.

261163136420 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 591197 + ... + 933723.

It is an arithmetic number, because the mean of its divisors is an integer number (11616837120).

Almost surely, 2^261163136420 is an apocalyptic number.

261163136420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261163136420 is an abundant number, since it is smaller than the sum of its proper divisors (296445045340).

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

261163136420 is a wasteful number, since it uses less digits than its factorization.

261163136420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343172 (or 343170 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 35.

Adding to 261163136420 its reverse (24631361162), we get a palindrome (285794497582).

The spelling of 261163136420 in words is "two hundred sixty-one billion, one hundred sixty-three million, one hundred thirty-six thousand, four hundred twenty".