21112289 has 4 divisors (see below), whose sum is σ = 23031600. Its totient is φ = 19192980.

The previous prime is 21112279. The next prime is 21112291. The reversal of 21112289 is 98221112.

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 21112289 - 2²⁰ = 20063713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21112279) 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, 959639 + ... + 959660.

It is an arithmetic number, because the mean of its divisors is an integer number (5757900).

Almost surely, 2^21112289 is an apocalyptic number.

It is an amenable number.

21112289 is a deficient number, since it is larger than the sum of its proper divisors (1919311).

21112289 is a wasteful number, since it uses less digits than its factorization.

21112289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1919310.

The product of its digits is 576, while the sum is 26.

The square root of 21112289 is about 4594.8110951376. The cubic root of 21112289 is about 276.3832847813.

The spelling of 21112289 in words is "twenty-one million, one hundred twelve thousand, two hundred eighty-nine".