21265380160 has 28 divisors (see below), whose sum is σ = 50638187268. Its totient is φ = 8506151936.

The previous prime is 21265380151. The next prime is 21265380167. The reversal of 21265380160 is 6108356212.

It can be written as a sum of positive squares in 2 ways, for example, as 10879324416 + 10386055744 = 104304^2 + 101912^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21265380167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33226837 + ... + 33227476.

Almost surely, 2^21265380160 is an apocalyptic number.

21265380160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21265380160 is an abundant number, since it is smaller than the sum of its proper divisors (29372807108).

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

21265380160 is an equidigital number, since it uses as much as digits as its factorization.

21265380160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66454330 (or 66454320 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 34.

The spelling of 21265380160 in words is "twenty-one billion, two hundred sixty-five million, three hundred eighty thousand, one hundred sixty".