261604521760000 has 720 divisors, whose sum is σ = 746933990362560. Its totient is φ = 90780549120000.

The previous prime is 261604521759989. The next prime is 261604521760007. The reversal of 261604521760000 is 67125406162.

It is a happy number.

261604521760000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261604521760007) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1912091595 + ... + 1912228405.

It is an arithmetic number, because the mean of its divisors is an integer number (1037408319948).

Almost surely, 2^{261604521760000} is an apocalyptic number.

261604521760000 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 261604521760000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (373466995181280).

261604521760000 is an abundant number, since it is smaller than the sum of its proper divisors (485329468602560).

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

261604521760000 is a wasteful number, since it uses less digits than its factorization.

261604521760000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136920 (or 136891 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 40.

The spelling of 261604521760000 in words is "two hundred sixty-one trillion, six hundred four billion, five hundred twenty-one million, seven hundred sixty thousand".