21282089 has 4 divisors (see below), whose sum is σ = 21968640. Its totient is φ = 20595540.

The previous prime is 21282083. The next prime is 21282103. The reversal of 21282089 is 98028212.

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 21282089 - 2⁴ = 21282073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21282083) 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, 343229 + ... + 343290.

It is an arithmetic number, because the mean of its divisors is an integer number (5492160).

Almost surely, 2^21282089 is an apocalyptic number.

It is an amenable number.

21282089 is a deficient number, since it is larger than the sum of its proper divisors (686551).

21282089 is an equidigital number, since it uses as much as digits as its factorization.

21282089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 686550.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 21282089 is about 4613.2514564025. The cubic root of 21282089 is about 277.1222639679.

The spelling of 21282089 in words is "twenty-one million, two hundred eighty-two thousand, eighty-nine".