21872852256689 has 4 divisors (see below), whose sum is σ = 24997545436224. Its totient is φ = 18748159077156.

The previous prime is 21872852256649. The next prime is 21872852256691. The reversal of 21872852256689 is 98665225827812.

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 21872852256689 - 2⁸ = 21872852256433 is a prime.

It is a super-3 number, since 3×21872852256689³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21872852256649) 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, 1562346589757 + ... + 1562346589770.

It is an arithmetic number, because the mean of its divisors is an integer number (6249386359056).

Almost surely, 2^{21872852256689} is an apocalyptic number.

It is an amenable number.

21872852256689 is a deficient number, since it is larger than the sum of its proper divisors (3124693179535).

21872852256689 is an equidigital number, since it uses as much as digits as its factorization.

21872852256689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3124693179534.

The product of its digits is 464486400, while the sum is 71.

The spelling of 21872852256689 in words is "twenty-one trillion, eight hundred seventy-two billion, eight hundred fifty-two million, two hundred fifty-six thousand, six hundred eighty-nine".