21046189 has 4 divisors (see below), whose sum is σ = 21056256. Its totient is φ = 21036124.

The previous prime is 21046171. The next prime is 21046217. The reversal of 21046189 is 98164012.

It is a happy number.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21046189 - 2²³ = 12657581 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 21046189.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21046139) 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, 589 + ... + 6514.

It is an arithmetic number, because the mean of its divisors is an integer number (5264064).

Almost surely, 2^21046189 is an apocalyptic number.

It is an amenable number.

21046189 is a deficient number, since it is larger than the sum of its proper divisors (10067).

21046189 is an equidigital number, since it uses as much as digits as its factorization.

21046189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10066.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 21046189 is about 4587.6125599270. The cubic root of 21046189 is about 276.0945424555.

The spelling of 21046189 in words is "twenty-one million, forty-six thousand, one hundred eighty-nine".