21835889 has 4 divisors (see below), whose sum is σ = 22099056. Its totient is φ = 21572724.

The previous prime is 21835867. The next prime is 21835907. The reversal of 21835889 is 98853812.

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 21835889 - 2²⁰ = 20787313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21835189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131459 + ... + 131624.

It is an arithmetic number, because the mean of its divisors is an integer number (5524764).

Almost surely, 2^21835889 is an apocalyptic number.

It is an amenable number.

21835889 is a deficient number, since it is larger than the sum of its proper divisors (263167).

21835889 is an equidigital number, since it uses as much as digits as its factorization.

21835889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263166.

The product of its digits is 138240, while the sum is 44.

The square root of 21835889 is about 4672.8887211232. Note that the first 3 decimals coincide. The cubic root of 21835889 is about 279.5054578253.

The spelling of 21835889 in words is "twenty-one million, eight hundred thirty-five thousand, eight hundred eighty-nine".