21765828853 has 4 divisors (see below), whose sum is σ = 21816330048. Its totient is φ = 21715327660.

The previous prime is 21765828817. The next prime is 21765828869. The reversal of 21765828853 is 35882856712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21765828853 - 2¹⁷ = 21765697781 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21765828794 and 21765828803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21765828893) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25249951 + ... + 25250812.

It is an arithmetic number, because the mean of its divisors is an integer number (5454082512).

Almost surely, 2^21765828853 is an apocalyptic number.

It is an amenable number.

21765828853 is a deficient number, since it is larger than the sum of its proper divisors (50501195).

21765828853 is an equidigital number, since it uses as much as digits as its factorization.

21765828853 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50501194.

The product of its digits is 6451200, while the sum is 55.

The spelling of 21765828853 in words is "twenty-one billion, seven hundred sixty-five million, eight hundred twenty-eight thousand, eight hundred fifty-three".