21072282809 has 8 divisors (see below), whose sum is σ = 21649235208. Its totient is φ = 20495721600.

The previous prime is 21072282793. The next prime is 21072282811. The reversal of 21072282809 is 90828227012.

It can be written as a sum of positive squares in 4 ways, for example, as 1135690000 + 19936592809 = 33700^2 + 141197^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21072282809 - 2⁴ = 21072282793 is a prime.

It is a super-2 number, since 2×21072282809² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21072282839) 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 7 ways as a sum of consecutive naturals, for example, 13109 + ... + 205709.

It is an arithmetic number, because the mean of its divisors is an integer number (2706154401).

Almost surely, 2^21072282809 is an apocalyptic number.

It is an amenable number.

21072282809 is a deficient number, since it is larger than the sum of its proper divisors (576952399).

21072282809 is a wasteful number, since it uses less digits than its factorization.

21072282809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195595.

The product of its (nonzero) digits is 64512, while the sum is 41.

The spelling of 21072282809 in words is "twenty-one billion, seventy-two million, two hundred eighty-two thousand, eight hundred nine".