21333006 has 36 divisors (see below), whose sum is σ = 48444552. Its totient is φ = 6771864.

The previous prime is 21332963. The next prime is 21333007. The reversal of 21333006 is 60033312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a self number, because there is not a number n which added to its sum of digits gives 21333006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21333007) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 93865 + ... + 94091.

It is an arithmetic number, because the mean of its divisors is an integer number (1345682).

Almost surely, 2^21333006 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21333006, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24222276).

21333006 is an abundant number, since it is smaller than the sum of its proper divisors (27111546).

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

21333006 is a wasteful number, since it uses less digits than its factorization.

21333006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 485 (or 255 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 18.

The square root of 21333006 is about 4618.7667185083. The cubic root of 21333006 is about 277.3430912314.

Adding to 21333006 its reverse (60033312), we get a palindrome (81366318).

The spelling of 21333006 in words is "twenty-one million, three hundred thirty-three thousand, six".