21227189 has 8 divisors (see below), whose sum is σ = 21855960. Its totient is φ = 20606976.

The previous prime is 21227177. The next prime is 21227201. The reversal of 21227189 is 98172212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21227177) and next prime (21227201).

It can be written as a sum of positive squares in 4 ways, for example, as 5026564 + 16200625 = 2242^2 + 4025^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21227189 - 2¹² = 21223093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21227989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3077 + ... + 7205.

It is an arithmetic number, because the mean of its divisors is an integer number (2731995).

Almost surely, 2^21227189 is an apocalyptic number.

It is an amenable number.

21227189 is a deficient number, since it is larger than the sum of its proper divisors (628771).

21227189 is an equidigital number, since it uses as much as digits as its factorization.

21227189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4279.

The product of its digits is 4032, while the sum is 32.

The square root of 21227189 is about 4607.2973639651. The cubic root of 21227189 is about 276.8837674358.

The spelling of 21227189 in words is "twenty-one million, two hundred twenty-seven thousand, one hundred eighty-nine".