261000661121320 has 64 divisors (see below), whose sum is σ = 621826375495680. Its totient is φ = 98254223778816.

The previous prime is 261000661121309. The next prime is 261000661121357. The reversal of 261000661121320 is 23121166000162.

It is a happy number.

261000661121320 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×261000661121320³ (a number of 44 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4335297 + ... + 23255023.

It is an arithmetic number, because the mean of its divisors is an integer number (9716037117120).

Almost surely, 2^{261000661121320} is an apocalyptic number.

261000661121320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261000661121320 is an abundant number, since it is smaller than the sum of its proper divisors (360825714374360).

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

261000661121320 is a wasteful number, since it uses less digits than its factorization.

261000661121320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18940042 (or 18940038 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The spelling of 261000661121320 in words is "two hundred sixty-one trillion, six hundred sixty-one million, one hundred twenty-one thousand, three hundred twenty".