261887995353600 has 2160 divisors, whose sum is σ = 1211809844250720. Its totient is φ = 53390853734400.

The previous prime is 261887995353553. The next prime is 261887995353619. The reversal of 261887995353600 is 6353599788162.

261887995353600 is a `hidden beast` number, since 2 + 6 + 1 + 8 + 8 + 7 + 9 + 9 + 5 + 3 + 5 + 3 + 600 = 666.

261887995353600 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-2 number, since 2×261887995353600² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 3290878611 + ... + 3290958189.

It is an arithmetic number, because the mean of its divisors is an integer number (561023076042).

Almost surely, 2^{261887995353600} is an apocalyptic number.

261887995353600 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 261887995353600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (605904922125360).

261887995353600 is an abundant number, since it is smaller than the sum of its proper divisors (949921848897120).

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

261887995353600 is a wasteful number, since it uses less digits than its factorization.

261887995353600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79691 (or 79660 counting only the distinct ones).

The product of its (nonzero) digits is 587865600, while the sum is 72.

The spelling of 261887995353600 in words is "two hundred sixty-one trillion, eight hundred eighty-seven billion, nine hundred ninety-five million, three hundred fifty-three thousand, six hundred".