21002212 has 36 divisors (see below), whose sum is σ = 46177600. Its totient is φ = 8181360.

The previous prime is 21002207. The next prime is 21002213. The reversal of 21002212 is 21220012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002213) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 289 + ... + 6487.

Almost surely, 2^21002212 is an apocalyptic number.

21002212 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 21002212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23088800).

21002212 is an abundant number, since it is smaller than the sum of its proper divisors (25175388).

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

21002212 is a wasteful number, since it uses less digits than its factorization.

21002212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6232 (or 6219 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 21002212 is about 4582.8170375873. The cubic root of 21002212 is about 275.9021041873.

Adding to 21002212 its reverse (21220012), we get a palindrome (42222224).

The spelling of 21002212 in words is "twenty-one million, two thousand, two hundred twelve".