21330012 has 24 divisors (see below), whose sum is σ = 54294912. Its totient is φ = 6463600.

The previous prime is 21329999. The next prime is 21330047. The reversal of 21330012 is 21003312.

It is a happy number.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21330012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80664 + ... + 80927.

It is an arithmetic number, because the mean of its divisors is an integer number (2262288).

Almost surely, 2^21330012 is an apocalyptic number.

21330012 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21330012 is an abundant number, since it is smaller than the sum of its proper divisors (32964900).

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

21330012 is a wasteful number, since it uses less digits than its factorization.

21330012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161609 (or 161607 counting only the distinct ones).

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

The square root of 21330012 is about 4618.4425946416. The cubic root of 21330012 is about 277.3301159688.

Adding to 21330012 its reverse (21003312), we get a palindrome (42333324).

It can be divided in two parts, 213300 and 12, that added together give a palindrome (213312).

The spelling of 21330012 in words is "twenty-one million, three hundred thirty thousand, twelve".