21761105265 has 24 divisors (see below), whose sum is σ = 38639234088. Its totient is φ = 11322850560.

The previous prime is 21761105263. The next prime is 21761105279. The reversal of 21761105265 is 56250116712.

21761105265 is a `hidden beast` number, since 2 + 17 + 6 + 110 + 526 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1359839376 + 20401265889 = 36876^2 + 142833^2 .

It is not a de Polignac number, because 21761105265 - 2¹ = 21761105263 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21761105263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5895474 + ... + 5899163.

It is an arithmetic number, because the mean of its divisors is an integer number (1609968087).

Almost surely, 2^21761105265 is an apocalyptic number.

It is an amenable number.

21761105265 is a deficient number, since it is larger than the sum of its proper divisors (16878128823).

21761105265 is a wasteful number, since it uses less digits than its factorization.

21761105265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11794689 (or 11794686 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 36.

The spelling of 21761105265 in words is "twenty-one billion, seven hundred sixty-one million, one hundred five thousand, two hundred sixty-five".