261665771325200 has 480 divisors, whose sum is σ = 727901378830080. Its totient is φ = 89337559449600.

The previous prime is 261665771325193. The next prime is 261665771325253. The reversal of 261665771325200 is 2523177566162.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 70095302534 + ... + 70095306266.

It is an arithmetic number, because the mean of its divisors is an integer number (1516461205896).

Almost surely, 2^{261665771325200} is an apocalyptic number.

261665771325200 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 261665771325200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (363950689415040).

261665771325200 is an abundant number, since it is smaller than the sum of its proper divisors (466235607504880).

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

261665771325200 is a wasteful number, since it uses less digits than its factorization.

261665771325200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5795 (or 5784 counting only the distinct ones).

The product of its (nonzero) digits is 6350400, while the sum is 53.

The spelling of 261665771325200 in words is "two hundred sixty-one trillion, six hundred sixty-five billion, seven hundred seventy-one million, three hundred twenty-five thousand, two hundred".