261245664000 has 432 divisors, whose sum is σ = 995353107840. Its totient is φ = 65566310400.

The previous prime is 261245663969. The next prime is 261245664007. The reversal of 261245664000 is 466542162.

261245664000 is a `hidden beast` number, since 2 + 6 + 1 + 2 + 4 + 5 + 6 + 640 + 0 + 0 = 666.

261245664000 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 (36).

It is not an unprimeable number, because it can be changed into a prime (261245664007) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 4869321 + ... + 4922679.

It is an arithmetic number, because the mean of its divisors is an integer number (2304058120).

Almost surely, 2^261245664000 is an apocalyptic number.

261245664000 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 261245664000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (497676553920).

261245664000 is an abundant number, since it is smaller than the sum of its proper divisors (734107443840).

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

261245664000 is a wasteful number, since it uses less digits than its factorization.

261245664000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53413 (or 53386 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The spelling of 261245664000 in words is "two hundred sixty-one billion, two hundred forty-five million, six hundred sixty-four thousand".