21033012 has 192 divisors, whose sum is σ = 70447104. Its totient is φ = 4700160.

The previous prime is 21033011. The next prime is 21033053.

It is a happy number.

21033012 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033011) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 204153 + ... + 204255.

It is an arithmetic number, because the mean of its divisors is an integer number (366912).

Almost surely, 2^21033012 is an apocalyptic number.

21033012 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21033012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35223552).

21033012 is an abundant number, since it is smaller than the sum of its proper divisors (49414092).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21033012 is a wasteful number, since it uses less digits than its factorization.

21033012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158 (or 156 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 12.

The square root of 21033012 is about 4586.1761850151. The cubic root of 21033012 is about 276.0369095776.

It can be divided in two parts, 2103 and 3012, that added together give a palindrome (5115).

The spelling of 21033012 in words is "twenty-one million, thirty-three thousand, twelve".