21189033 has 10 divisors (see below), whose sum is σ = 31652874. Its totient is φ = 14125968.

The previous prime is 21189019. The next prime is 21189041. The reversal of 21189033 is 33098112.

It can be written as a sum of positive squares in only one way, i.e., 18045504 + 3143529 = 4248^2 + 1773^2 .

It is not a de Polignac number, because 21189033 - 2⁴ = 21189017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 21188988 and 21189006.

It is not an unprimeable number, because it can be changed into a prime (21189533) 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 9 ways as a sum of consecutive naturals, for example, 130716 + ... + 130877.

Almost surely, 2^21189033 is an apocalyptic number.

It is an amenable number.

21189033 is a deficient number, since it is larger than the sum of its proper divisors (10463841).

21189033 is an equidigital number, since it uses as much as digits as its factorization.

21189033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261605 (or 261596 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 21189033 is about 4603.1546791304. The cubic root of 21189033 is about 276.7177678548.

It can be divided in two parts, 21 and 189033, that multiplied together give a palindrome (3969693).

The spelling of 21189033 in words is "twenty-one million, one hundred eighty-nine thousand, thirty-three".