21227089 has 4 divisors (see below), whose sum is σ = 22859956. Its totient is φ = 19594224.

The previous prime is 21227081. The next prime is 21227099. The reversal of 21227089 is 98072212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2016400 + 19210689 = 1420^2 + 4383^2 .

It is not a de Polignac number, because 21227089 - 2³ = 21227081 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21227089.

It is not an unprimeable number, because it can be changed into a prime (21227081) 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, 816414 + ... + 816439.

It is an arithmetic number, because the mean of its divisors is an integer number (5714989).

Almost surely, 2^21227089 is an apocalyptic number.

It is an amenable number.

21227089 is a deficient number, since it is larger than the sum of its proper divisors (1632867).

21227089 is a wasteful number, since it uses less digits than its factorization.

21227089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1632866.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 21227089 is about 4607.2865116031. The cubic root of 21227089 is about 276.8833326409.

The spelling of 21227089 in words is "twenty-one million, two hundred twenty-seven thousand, eighty-nine".